CN106369959B - A kind of air energy heat pump agricultural product drying device - Google Patents

Abstract

The invention relates to an air energy heat pump drying device for agricultural products. Consists of air source heat pump outdoor main unit, total heat exchanger, fan 1, condenser, material tray, drying box shell, windshield, exhaust pipe, air supply pipe, air supply plenum, and return air plenum . The outdoor main unit of the air source heat pump includes three air volume regulating valves and two sets of evaporators; the two sets of evaporators are connected in parallel, and are connected in series with the condenser through the refrigerant pipeline to form a part of the refrigeration cycle; the outdoor fresh air processed by the outdoor main unit of the air source heat pump is in the The total heat exchanger exchanges heat with the exhaust air and sends it into the shell of the drying box; the fan 1 provides the power to circulate the air in the shell of the drying box; install the windshield at the front and back of the material tray to obtain the required The air flow path in the material tray. The invention can realize three drying conditions of single heating, low-temperature dehumidification, and heating and dehumidification of agricultural products, and can also realize uniform air speed of the material tray, thereby improving energy utilization efficiency and drying uniformity of agricultural products.

Description

An air energy heat pump drying device for agricultural products

technical field

The invention relates to an air energy heat pump utilization technology, specifically an air energy heat pump agricultural product drying device with energy saving, environmental protection, high efficiency and stable operation, belonging to the fields of air energy heat pump application and agricultural product processing.

Background technique

According to statistics from the Ministry of Agriculture, the loss of agricultural products in my country due to drying problems is astonishing, with a loss rate of more than 8%, and the annual grain loss is as high as 50 billion catties. Therefore, the Ministry of Agriculture pointed out in the deployment of key tasks for agricultural product processing in 2015 that it will upgrade agricultural product drying facilities and equipment. The moisture content of agricultural products is high, and the energy consumption required for drying is large. For example, the moisture content of 1Kg of fruits and vegetables is above 90%, while the moisture content of dehydrated vegetables is generally below 4%. To dry 1000Kg of fruits and vegetables, if the energy loss is not considered, the theoretically required energy consumption is 1.9×10 ⁶ KJ, equivalent to 65Kg of standard coal. With the rapid development of agricultural product processing industry, the ever-increasing energy consumption of agricultural product drying has become an important part of my country's energy consumption.

In recent years, my country has achieved rapid development both in the research of agricultural product drying technology and in the development of equipment, and the current technology and equipment have basically synchronized with the world. However, there are still some deficiencies and problems in my country's agricultural product drying technology research and equipment research and development. For example: 1) my country’s agricultural product drying and heating energy is still mainly coal-fired, especially some hot air drying rooms suitable for drying a variety of agricultural product materials mostly use hand-fired coal-fired heating furnaces for drying. Tension, further research and development of energy-saving drying technology and equipment using renewable energy is the future development direction. 2) There are many types of technologies and equipment commonly used in the drying and processing of agricultural products, including batch static hot air circulation drying room, tunnel hot air drying technology, belt continuous hot air drying technology, radiation drying technology, vacuum freeze drying technology Wait. There are many types of drying technologies. However, in the drying application of various technologies today, there are problems of high energy consumption and uniformity of the drying process. The drying degree of the materials in the drying box is not the same, which causes the turnover of the materials in the drying process to increase the manual workload, and the long drying time increases the energy consumption, which leads to the increase of the processing cost of agricultural products.

Therefore, on the basis of the existing drying technology for agricultural products, the drying technology and equipment should be further developed from the aspects of drying energy consumption and product quality, and an air energy heat pump drying device for agricultural products with energy saving, environmental protection, high efficiency and stable operation should be designed. , is an important guarantee for the sustainable and stable development of my country's agricultural industry and agricultural product processing industry, and is also one of the important problems that the current agricultural product drying technology is facing.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the current drying technology for agricultural products and propose a product drying device using air energy. The drying device can realize single heating and drying of agricultural products in different climates by using an air energy heat pump as a heat source. , Drying functions such as single dehumidification and drying, dehumidification and heating and drying.

In order to solve the above technical problems, the technical solution adopted by the present invention is: an air source heat pump agricultural product drying device, which includes an air source heat pump outdoor main unit, a total heat exchanger, fan 1, a condenser, a material tray, and a drying box Shell, windshield, exhaust pipe 1, air supply pipe 1, exhaust pipe 2, air supply pipe 2, air volume control valve 1, air volume control valve 2, air volume control valve 3, evaporator 1, evaporator 2, fan 2. Air supply static plenum and return air static plenum; the air source heat pump outdoor host includes air volume regulating valve 1, air volume regulating valve 2, air volume regulating valve 3, evaporator 1, evaporator 2, and fan 2; The first evaporator and the second evaporator are connected in parallel through the refrigerant pipeline, and form a part of the refrigeration cycle through the refrigerant pipeline and the condenser in series; The heat exchanger is connected, the total heat exchanger is connected with the air supply pipe 1, the air supply pipe 1 passes through the side wall of the drying box and extends to the vicinity of the fan 1, the outlet of the fan 1 is connected with the air supply static pressure chamber, and the air supply static pressure The chamber is connected to one side of the material tray, and the other side of the material tray is connected to the return air static pressure chamber; the windshield is installed at the front and rear of the material tray to change the flow direction of the air supply in the material tray, so that All the air supply passes through the material tray and only passes through one layer of the material tray; the exhaust pipe is installed near the outlet of the return air plenum chamber in the shell of the drying box, and the exhaust pipe is connected to the total heat exchanger , the total heat exchanger is connected to the exhaust pipe two, and the condenser is installed in the air supply static pressure chamber.

The advantages and positive effects of the present invention are: 1) The outdoor main unit of the air source heat pump is designed as two zones and two independent evaporators, and each zone is provided with an independent air outlet and an air volume regulating valve. The valve is opened and closed, and the fan in the air source heat pump main engine and the fan of the total heat exchanger are adjusted to start and stop, which can realize three drying processes of the drying box for agricultural products: single heating drying, low temperature dehumidification drying, heating and dehumidification drying. In other cases, the same drying device can meet the needs of different agricultural products drying processes. 2) Set appropriate amount of air baffles on both sides of the material tray in the drying area to change the airflow distribution in the drying area, so that all the hot air from the air supply static pressure chamber passes through the material tray, and all the hot air from the air supply static pressure chamber The hot air in the pressure chamber only passes through the material tray once and then enters the return air static pressure chamber, which can realize the uniform air velocity of each layer of material tray and each point in the material tray, which improves the utilization rate of hot air and the uniformity of drying of agricultural products. Save energy consumption and drying time for drying agricultural products, and improve energy utilization efficiency. 3) A total heat exchanger is designed to exchange heat between the high-temperature and high-humidity exhaust air with high enthalpy and the low-temperature and low-humidity supply air with low enthalpy after dehumidification, which can obtain higher heat exchange efficiency and save drying energy consumption. 4) Using the air source heat pump, the renewable energy of air energy is used as the heat source for drying agricultural products, which is conducive to saving energy and protecting the environment.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Figure 2 is a schematic diagram of the outdoor host of the air source heat pump

Figure 1 - Figure 2: 1. Air source heat pump outdoor main unit, 2. Total heat exchanger, 3. Fan 1, 4. Condenser, 5. Material tray, 6. Drying box shell, 7. Windshield, 8. Exhaust pipe 1, 9. Air supply pipe 1, 10. Exhaust pipe 2, 11. Air supply pipe 2, 12. Air volume control valve 1, 13. Air volume control valve 2, 14. Air volume control valve 3, 15 . Evaporator 1, 16. Evaporator 2, 17. Fan 2, 18. Air supply plenum, 19. Return air plenum.

Detailed ways

In order to further understand the content, characteristics and effects of the present invention, the following embodiments are listed below, and detailed descriptions are given below with reference to the accompanying drawings.

As shown in Figure 1-Figure 2:

Air source heat pump outdoor main unit 1, total heat exchanger 2, fan 1 3, condenser 4, material tray 5, drying box shell 6, windshield 7, exhaust pipe 18, air supply pipe 19, exhaust Pipe two 10, air supply pipe two 11, air volume regulating valve one 12, air volume regulating valve two 13, air volume regulating valve three 14, evaporator one 15, evaporator two 16, fan two 17, air supply static pressure chamber 18, return Air static plenum 19; the air source heat pump outdoor host 1 includes air volume regulating valve one 12, air volume regulating valve two 13, air volume regulating valve three 14, evaporator one 15, evaporator two 16, fan two 17; The first evaporator 15 and the second evaporator 16 are connected in parallel through the refrigerant pipeline, and form a part of the refrigeration cycle through the refrigerant pipeline and the condenser 4 in series; Pipe two 11 is connected with the total heat exchanger 2, and the total heat exchanger 2 is connected with the air supply pipe one 9, and the air supply pipe one 9 passes through the side wall of the drying box shell 6 and extends to the vicinity of the fan one 3, and the fan one 3 exits It is connected to the air supply static plenum 18, the air supply static plenum 18 is connected to one side of the material tray 5, and the other side of the material tray 5 is connected to the return air static plenum 19; the windshield 7 is installed on the material The front and rear parts of the tray 5 change the flow direction of the air supply in the material tray 5 so that all the air supply passes through the material tray 5 and only passes through one layer of the material tray 5; the exhaust pipe-8 is installed in the oven Near the outlet of the return air static plenum 19 in the dry box shell 6, the exhaust pipe one 8 is connected with the total heat exchanger 2, and the total heat exchanger 2 is connected with the exhaust pipe two 10, and the described condenser 4 is installed in the delivery In the air static pressure chamber 18.

The operation of an air energy heat pump agricultural product drying device of the present invention can be divided into three drying modes: single heating drying, low temperature dehumidification drying, heating and dehumidification drying, etc. The selection of the three drying modes can be based on The characteristics of agricultural products and the requirements of processing technology are determined, and the operation of each working condition is as follows.

The specific operation of the single heating and drying condition is: open the air volume regulating valve 12, close the air volume regulating valve 2 13, and open the air volume regulating valve 3 14; open the outdoor host 1 of the air source heat pump, open the fan 2 17, Under the action of gravity, the outdoor air flows through the first evaporator 15 or the second evaporator 16, the first evaporator 15 and the second evaporator 16 absorb the heat of the outdoor air, and send the heat to the condenser 4 after the temperature is raised by the outdoor host 1 of the air source heat pump ; fan one 3 is opened to circulate the air in the drying box, after the outlet air of fan one 3 is heated by condenser 4, it is sent into the material tray 5 to dry the material through the air supply static pressure chamber 18, and enters the return air static pressure chamber 19, Flow back to the blower fan one 3; the total heat exchanger 2 is closed, and fresh air is not added to the drying box. This working condition only supplies heat to the drying box, heats and dries the material in the material tray 5, and does not send outdoor fresh air to the drying box.

The specific operation of low-temperature dehumidification and drying conditions is as follows: air volume control valve 1 is closed at 12, air volume control valve 2 is opened at 13, air volume control valve 3 is closed at 14; fan 2 is closed at 17, total heat exchanger 2 is opened, and the outdoor host of the air source heat pump is 1 When it is turned on, under the action of the fan gravity of the total heat exchanger 2, the outdoor fresh air flows through the evaporator 16 and the evaporator 15 in sequence, and the dry fresh air after two-stage cooling and dehumidification enters the total heat exchanger 2, and the total heat exchange After heat exchange with the exhaust air in the device 2, it enters the drying box. The outdoor dry fresh air is mixed with the return air in the drying box, then pressurized by the fan-3, heated by the condenser 4, and sent into the air supply static pressure chamber 18. The material tray 5 dries the material and enters the return air static plenum 19, a part of the return air flows to the fan one 3, and the other part of the return air enters the total heat exchanger 2 through the exhaust pipe one 8 for heat exchange and is discharged to the outside. This working condition is mainly to send low-temperature dry air into the drying box, and at the same time transfer the heat of cooling and dehumidification to the low-temperature dry fresh air through the outdoor main unit 1 of the air source heat pump and the condenser 4, so that the temperature of the low-temperature dry air will rise and obtain a lower temperature. The relative humidity of the air is more conducive to drying materials at low temperature.

The heating and dehumidification drying conditions can be divided into two operating modes, that is, the operation mode with high outdoor air humidity content and the operation mode with low outdoor air humidity content. The specific operation of the operation mode with high outdoor air humidity content is: air volume control valve One 12 is turned on, air volume control valve 2 13 is opened, air volume control valve 3 14 is closed; fan 2 17 is turned on, total heat exchanger 2 is turned on, air source heat pump outdoor host 1 is turned on, and part of the outdoor fresh air is under the gravitational force of fan 2 17. After heat exchange with evaporator 2 16, it is discharged through fan 2 17; another part of outdoor fresh air flows through evaporator 2 16 and evaporator 1 15 in turn under the action of the fan gravity of total heat exchanger 2, and is cooled and dehumidified in two stages The final dry fresh air enters the total heat exchanger 2, exchanges heat with the exhaust air in the total heat exchanger 2, and then enters the drying box; the outdoor main unit 1 of the air source heat pump converts the heat absorbed by the evaporator 16 and the evaporator 15 Passed to the condenser 4; the outdoor dry fresh air is mixed with the return air in the drying box, then pressurized by the fan one 3 and heated by the condenser 4, and sent to the material tray 5 to dry the material through the air supply static pressure chamber 18, and enter the return air In the static plenum 19, a part of the return air flows to the fan one 3, and the other part of the return air enters the total heat exchanger 2 through the exhaust pipe one 8 for heat exchange and is discharged to the outside. In the outdoor air low humidity operation mode, due to the low air humidity (such as outdoor air in winter), there is no need to dehumidify the outdoor air, and only need to heat the air to obtain a lower air relative humidity. Therefore, the specific operation is as follows: : The air volume regulating valve three 14 is opened, and other operations are the same as the specific operation of the outdoor air high humidity operation mode; under this operation mode, the air used as the heat source of the heat pump flows through the fan two 17, and the air source includes two parts: one part flows through the evaporation The second part 16 exchanges heat with the evaporator 16, and the other part enters through the air volume regulating valve 3 14 and exchanges heat with the evaporator 15; the dry air of the drying box comes from the outdoor fresh air, flows through the air volume regulating valve 3 14, and the air volume After adjusting the valve 2 13 and the total heat exchanger 2, it directly enters the drying box. This working condition can supply heat and send dry fresh air to the drying box at the same time, and can heat and dehumidify the material.

Claims (1)

1. a kind of air energy heat pump agricultural product drying device, it is characterised in that：The agricultural product drying device includes air-source Heat pump outdoor host computer (1), total-heat exchanger (2), wind turbine one (3), condenser (4), material disc (5), drying box enclosure (6), gear Aerofoil (7), exhaust duct one (8), ajutage one (9), exhaust duct two (10), ajutage two (11), volume damper one (12), wind Adjustable valve two (13), volume damper three (14), evaporator one (15), evaporator two (16), wind turbine two (17), static pressure of blowing Room (18), return air plenum chamber (19)；The air source heat pump outdoor host computer (1) includes volume damper one (12), air quantity tune Save valve two (13), volume damper three (14), evaporator one (15), evaporator two (16), wind turbine two (17)；The evaporator One (15) and evaporator two (16) are connected in parallel by refrigerant tubing, and are connected with condenser (4) structure by refrigerant tubing At a part for refrigeration cycle；The volume damper two (13) of the air source heat pump outdoor host computer (1) passes through ajutage two (11) it is connect with total-heat exchanger (2), total-heat exchanger (2) is connect with ajutage one (9), and ajutage one (9) passes through drying box Shell (6) side wall simultaneously reaches near wind turbine one (3), and wind turbine one (3) outlet is connect with air-supply plenum chamber (18), plenum chamber of blowing (18) it is connect with the side of material disc (5), the other side of material disc (5) is connect with return air plenum chamber (19)；The wind shield (7) it is installed on the front and rear of material disc (5), changes flow direction of blowing in material disc (5), all air-supplies is made to both pass through object Charging tray (5) and just through one layer of material disc (5)；The return air that the exhaust duct one (8) is mounted in drying box enclosure (6) is quiet Pressure chamber (19) near exit, exhaust duct one (8) are connect with total-heat exchanger (2), and total-heat exchanger (2) connects with exhaust duct two (10) It connects, the condenser (4) is installed in air-supply plenum chamber (18)；

The operation of the air energy heat pump agricultural product drying device is divided into single heating, drying, low temperature dehumidification drying, heating and dehumidifying Three kinds of drying operating modes of drying；

Under single heating, drying operating mode, the volume damper one (12) is opened, the volume damper two (13) is closed, The volume damper three (14) is opened；Air source heat pump outdoor host computer (1) is opened, and the wind turbine two (17) is opened, described Under the graviational interaction of wind turbine two (17), outdoor air flows through the evaporator one (15) or the evaporator two (16)；Described Low temperature dehumidification is dried under operating mode, and the volume damper one (12) is closed, the volume damper two (13) is opened, the air quantity Regulating valve three (14) is closed；The wind turbine two (17) is closed, and the total-heat exchanger (2) is opened, air source heat pump outdoor host computer (1) it opens, under the wind turbine graviational interaction of the total-heat exchanger (2), outdoor fresh air is followed by the evaporator two (16) With the evaporator one (15)；

The heating and dehumidifying drying operating mode are divided into the high water capacity operational mode of outdoor air and the low water capacity of outdoor air is run Pattern, under the high water capacity operational mode of the outdoor air, the volume damper one (12) opening, the volume damper Two (13) are opened, the volume damper three (14) is closed；The wind turbine two (17) is opened, and the total-heat exchanger (2) is opened, Air source heat pump outdoor host computer (1) is opened, and a part of outdoor fresh air is under the graviational interaction of the wind turbine two (17), with the steaming It sends out after device two (16) carries out heat exchange and is discharged by the wind turbine two (17)；Another part outdoor fresh air is in the total-heat exchanger (2) under wind turbine graviational interaction, followed by the evaporator two (16) and the evaporator one (15)；

Under the low water capacity operational mode of the outdoor air, the volume damper three (14) open, it is other operation with it is described The concrete operations of the high water capacity operational mode of outdoor air are identical, and under the operational mode, the air as source heat pump heat flows through institute Wind turbine two (17) is stated, air source includes two parts：A part flow through the evaporator two (16) and with the evaporator two (16) it exchanges heat with the evaporator one (15) after heat exchange, another part are entered by the volume damper three (14)；Drying box Dry air comes from outdoor fresh air, flows through the volume damper three (14), the volume damper two (13) and described complete Heat exchanger is directly entered after (2) in drying box.