CN102767937B - Greenhouse type solar heat pump combined drying device and method - Google Patents

Abstract

The invention relates to a solar drying device, and specifically discloses a greenhouse-type solar heat pump combined drying device and method. The device includes: a greenhouse; a return air fan, which is arranged inside the greenhouse, one end of which is a return air outlet, and the other end is an exhaust and pass through the side wall of the greenhouse through the air return pipe to extend out of the greenhouse; the fresh air fan is located outside the greenhouse, one end of which is a fresh air outlet, and the other end is an air supply outlet and passes through the greenhouse through the air supply pipe The side wall extends into the greenhouse; the drying bed is arranged inside the greenhouse; the control center is connected with the return air fan and the fresh air fan. The invention can save energy and efficiently utilize the heat of solar energy to heat and dry the materials in the greenhouse.

Description

Greenhouse type solar heat pump combined drying device and method

technical field

The present invention relates to the technical field of solar drying devices, in particular to a greenhouse-type solar heat pump combined drying device and method.

Background technique

With the in-depth implementation of energy conservation and emission reduction policies, the use of solar energy is becoming more and more extensive. While developing solar power generation and other methods, the ancient solar thermal utilization has been re-emphasized. The solar energy used in the thermal utilization of solar energy is a low-grade energy. In addition to being used in water heaters, the role of solar energy in the low-temperature (<100°C) drying field is being more and more discovered. Solar drying devices are mainly divided into: greenhouse type, heat collection type and the combination of the two. Among them, the greenhouse of the greenhouse type solar drying device is a drying room, and the drying room directly receives the sun's radiant energy. This drying device is actually a solar greenhouse with moisture removal capacity, and its main point is that the heat collecting component is integrated with the drying chamber. When working, the sunlight directly shines on the items to be dried through the glass cover, and part of the sunlight is absorbed by the greenhouse wall, so the indoor temperature gradually rises, and the evaporated water of the items is taken away by air convection, and discharged from the exhaust chimney to achieve the purpose of drying . However, the heat energy in the exhaust gas of this traditional structure is directly lost and cannot be recycled, and when it is suitable for industrial drying, the energy density is too low and the continuity is poor, which cannot meet the production requirements.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the invention is how to heat and dry materials in the greenhouse by energy-saving and efficient use of solar heat.

(2) Technical solutions

In order to solve the above technical problems, the present invention provides a greenhouse-type solar heat pump combined drying device, comprising:

greenhouse;

The air return fan is arranged inside the greenhouse, one end of which is an air return port, and the other end is an exhaust port, and the air return pipe passes through the side wall of the greenhouse and extends out of the greenhouse;

The fresh air fan is located outside the greenhouse, one end of which is a fresh air outlet, and the other end is an air supply outlet and extends into the greenhouse through the air supply pipe through the side wall of the greenhouse;

a drying bed arranged inside the greenhouse;

The control center is connected with the return air blower and the fresh air blower.

In a further technical solution, it also includes:

a condenser, located in the greenhouse, arranged on the air supply pipe, one end of which is the air supply port;

The evaporator, located outside the greenhouse, is connected between the return air pipe and the air supply pipe through an evaporation pipe, and the evaporator is connected with the condenser through two loops.

Also includes:

The expansion valve and the compressor are connected with the control center and respectively located in the two circuits connecting the evaporator and the condenser.

Also includes:

The heat exchanger is connected between the return air fan and the evaporator through the return air pipe, and is connected between the evaporator and the condenser through the air supply pipe.

Wherein, the evaporation pipe of the evaporator close to the exhaust port is provided with a second air valve, and the evaporation pipe of the evaporator close to the fresh air fan is provided with a fourth air valve, and the second air valve and the fourth air valve are connected to the control center.

One end of the air return pipe near the exhaust port is provided with a first air valve, and one end of the air supply pipe near the fresh air fan is provided with a third air valve, and both the first air valve and the third air valve are connected with each other. Control Center connection.

The drying bed is provided with a mud turning machine.

A turbulent fan is fixed on the inner top of the greenhouse through a steel frame.

The greenhouse is provided with a material inlet door and a material outlet door.

In order to solve the above technical problems, the present invention also provides a greenhouse-type solar heat pump combined drying method, comprising the following steps:

Step S1. The control center detects whether the solar intensity reaches the first set value that meets the dehumidification needs of the greenhouse. If yes, execute step S2. Otherwise, judge whether the solar intensity is between the first set value and the second set value. If yes, then Execute step S3;

Step S2, the control center controls to close the second damper and the fourth damper, open the first damper and the third damper, and execute step S21;

Step S21, the air in the greenhouse is pumped by the return air fan through the air return port and discharged through the return air pipe and the exhaust port, and the air outside the greenhouse is pumped by the fresh air fan through the fresh air port and sent into the greenhouse through the air supply pipe and the air supply port;

Step S3 The control center controls the opening of the first air valve to the fourth air valve, and the control center calculates and controls the opening of each air valve according to the intensity of solar energy, and determines the flow direction and distribution of return air and supply air, so as to realize the indoor heat demand supply balance.

The step S1 also includes:

If the control center detects that the solar intensity is lower than the second set value, step S4 is executed.

Also includes:

Step S4, the control center controls to close the first damper and the third damper, open the second damper and the fourth damper, the heat of the hot and humid air from the greenhouse in the evaporator is absorbed by the heat pump working fluid of the evaporator, and the damp heat The moisture in the air is condensed and discharged, the heat pump working fluid of the evaporator enters the compressor to be further heated and pressurized, the heated and pressurized heat pump working fluid enters the condenser, and the heat pump working fluid in the condenser The dehumidified air in the evaporator also enters the condenser and exchanges heat with the heat pump working fluid of the condenser. The temperature of the heat pump working fluid of the condenser decreases, and the heat pump working fluid after the temperature drops passes through the expansion valve. Further lowering the temperature and pressure, entering the evaporator for the next round of absorbing the heat of hot and humid air, and the hot air after heat exchange in the condenser is sent into the greenhouse through the air outlet.

Also includes:

The hot and humid air in the greenhouse discharged from the return air fan exchanges heat with the air cooled by the evaporator in the preheater.

(3) Beneficial effects

The above technical scheme has the following beneficial effects:

1. The present invention belongs to the equipment for drying sludge by using greenhouse solar heat, which not only meets the area requirement of collecting solar energy, but also plays the role of sludge warehouse, and the cost is much lower than that of solar collectors;

2. In the present invention, the heat pump unit is supplemented with solar energy, and the greenhouse is sealed to recover the heat in the greenhouse as much as possible, and the efficiency of the heat pump under this working condition will be greatly improved, and the purpose of high efficiency and energy saving is well achieved ;

3. The adjustment method of the heat pump evaporator (absorbing heat from the return air or ambient heat) can be coordinated to achieve dehumidification and heat supplementation at the same time, making the operation of the entire system more stable.

Description of drawings

Fig. 1 is a schematic structural view of a greenhouse-type solar heat pump combined drying device according to an embodiment of the present invention;

Fig. 2 is the sectional view of the combined drying device of greenhouse type solar heat pump according to the embodiment of the present invention;

Fig. 3 is the top view of the greenhouse type solar heat pump combined drying device of the embodiment of the present invention;

Fig. 4 is a partial structural schematic diagram of a greenhouse-type solar heat pump combined drying device according to an embodiment of the present invention;

Fig. 5 is a flow chart of a combined drying method of a greenhouse-type solar heat pump according to an embodiment of the present invention.

Among them, 1: greenhouse; 2: return air pipe; 3: air supply pipe; 4: return air outlet; 5: return air fan; 6: heat exchanger; 7: second air valve; 8: first air valve; 9 : exhaust port; 10: evaporator; 11: condenser; 12: air supply port; 13: third air valve; 14: fourth air valve; 15: fresh air fan; 16: fresh air port; 17: discharge door; 18: Feed door; 19: Mud turning machine; 20: Disturbance fan; 21: Steel frame; 23: Drying bed; 24: Sludge material; 25: Expansion valve; 26: Compressor; 27: Evaporation tube.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

As shown in Figure 1, it is a schematic structural diagram of a greenhouse-type solar heat pump combined drying device according to an embodiment of the present invention; the device includes a greenhouse 1, a return air fan 5, a heat exchanger 6, a condenser 11, an evaporator 10, and a fresh air fan 15 , compressor 26, expansion valve 25, several dampers and a control center (not shown). Wherein the condenser 11, the evaporator 10, the compressor 26 and the expansion valve 25 constitute a heat pump unit.

Wherein, the greenhouse 1 is made of PC solar panels, or the top and sides of the greenhouse 1 that can be exposed to sunlight are made of PC solar panels. There is a return air fan 5 inside the greenhouse 1, one end of the return air fan 5 is the return air outlet 4, and the other end passes through the side wall of the greenhouse 1 through the return air pipe 2 and is connected with the heat pump preheating heat exchanger 6 outside the greenhouse 1, and the return air The pipe 2 continues to extend after being connected to the heat exchanger 6 , and the other end of the air return pipe 2 is an exhaust port 9 . A condenser 11 is installed inside the greenhouse 1, one end of the condenser 11 is an air supply port 12, and the other end is connected to the heat exchanger 6 through the side wall of the greenhouse 1 through the air supply pipe 3, and the air supply pipe 3 is connected to the heat exchanger 6 Continue to extend afterwards, be connected with the fresh air blower 15, and the other end of the fresh air blower 15 is the fresh air outlet 16.

The air return pipe 2 and the air supply pipe 3 are also connected to the evaporator 10 through the evaporation pipe 27. The evaporation pipe 27 is provided with a second damper 7 near the return air pipe 2, and the evaporation pipe 27 is provided with a valve near the air supply pipe 3. The fourth damper 14. A first air valve 8 is provided at a position between the air outlet 9 and the second air valve 7 in the return air pipe 2, and a first air valve 8 is provided at a position between the fresh air blower 15 and the fourth air valve 14 in the air supply pipe 3. Three dampers 13. Each damper is connected with the control center.

The evaporator 10 is also connected to the condenser 11 through a compressor 26 and an expansion valve 25, respectively. Wherein the compressor 26 is located inside the greenhouse 1 and the expansion valve 25 is located outside the greenhouse 1 . The compressor 26 and the expansion valve 25 are connected to the control center.

The greenhouse 1 is provided with a drying bed 23 for placing sludge materials 24 . The greenhouse 1 is provided with an inlet door 18 and an outlet door 17 for sending the sludge material 24 into the drying bed 23 inside the greenhouse 1 and sending out the dried sludge material 24 . The drying bed 23 is provided with a track between the feed door 18 and the discharge door 17, on which a mud turner 27 moves back and forth along the track, continuously destroying the dense structure formed on the drying surface of the sludge material 7 to improve water discharge efficiency.

The top of the greenhouse 1 is fixed with a turbulence fan 20 through a steel frame 21, which is used to blow air to the sludge material 7, so that the air in the greenhouse 1 rolls up and down to make the water fully diffuse therein.

As shown in Figure 5, it is a flow chart of the greenhouse-type solar heat pump combined drying method of the embodiment of the present invention, which is also the principle of the device provided by the present invention, including the following steps:

Step S1. The control center detects whether the solar intensity is greater than the first set value that meets the dehumidification needs of the greenhouse. If yes, execute step S2. Otherwise, judge whether the solar intensity is between the first set value and the second set value, then execute Step S3; if the solar intensity is lower than the second set value, execute step S4;

Step S2, the control center controls to close the second air valve and the fourth air valve, and judges whether the preset exhaust point is reached, if yes, execute step S21;

Step S21, open the first air valve and the third air valve, the air with high temperature and high humidity in the greenhouse is drawn by the return air fan through the return air outlet, and is discharged through the return air pipe and the exhaust port, and the air with low temperature and low humidity outside the greenhouse The air is pumped by the fresh air fan through the fresh air outlet and sent into the greenhouse through the air supply pipe and the air supply outlet;

This part of fresh air is heated by solar energy in the greenhouse, and then becomes high-temperature and high-humidity air. When it is discharged, it takes away the moisture in the sludge to achieve the purpose of dehumidification.

Step S3, the control center determines whether the preset exhaust point is reached, and if so, controls the opening of the first air valve to the fourth air valve, and the control center calculates and controls the opening of each air valve according to the intensity of solar energy to determine the opening of the heat pump unit. And determine the flow direction and distribution of return air and supply air to achieve the balance of indoor heat demand and supply.

Step S4, the control center controls to close the first damper and the third damper, and open the second damper and the fourth damper. Turn on the heat pump unit, specifically, the heat from the hot and humid air in the greenhouse in the evaporator is absorbed by the heat pump working fluid of the evaporator, and the moisture in the hot and humid air is condensed and discharged, so as to achieve the purpose of dehumidifying the hot and humid air in the greenhouse; The heat pump working fluid enters the compressor and is further heated and pressurized. The heated and pressurized heat pump working fluid enters the condenser and exchanges heat with the heat pump working fluid in the condenser; its heat is absorbed by the heat pump working fluid in the condenser. Absorption, the dehumidified and cooled air in the evaporator enters the condenser, the heat of the heat pump working fluid in the condenser is absorbed by the air entering the condenser, the temperature of the heat pump working medium decreases, and the cooled heat pump working fluid passes through the expansion valve Further lower the temperature and pressure, enter the evaporator to absorb the heat of the hot and humid air in the next round; and the hot air after the heat exchange of the condenser continues to enter the greenhouse through the air outlet. At the same time, the hot and humid air discharged from the return air fan in the greenhouse and the air cooled by the evaporator perform a round of heat exchange in the preheater to make full use of the heat of the hot and humid air in the greenhouse.

According to the actual situation, when the heat of the indoor hot and humid air is not enough, other heat sources can be introduced into the evaporator, such as ambient air or water, and the heat pump can absorb the heat from the outside to supplement the heat dissipation in the greenhouse to achieve balance.

After adopting above-mentioned device and method, compared with prior art, the present invention has following beneficial effect:

1. The present invention belongs to the equipment for drying sludge by using greenhouse solar heat, which not only meets the area requirement of collecting solar energy, but also plays the role of sludge warehouse, and the cost is much lower than that of solar collectors;

2. In the present invention, the heat pump unit is supplemented with solar energy, and the greenhouse is sealed to recover the heat in the greenhouse as much as possible, and the efficiency of the heat pump under this working condition will be greatly improved, and the purpose of high efficiency and energy saving is well achieved ;

3. The adjustment method of the heat pump evaporator (absorbing heat from the return air or ambient heat) can be coordinated to achieve dehumidification and heat supplementation at the same time, making the operation of the entire system more stable.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made, these improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (6)

1. greenhouse type combined solar energy heat pump drying device, is characterized in that, comprising:

Greenhouse, described greenhouse inner top is fixed with flow-disturbing blower fan by steelframe;

Return air fan, is arranged on described inside greenhouse, and its one end is return air inlet, and the other end is exhaust outlet and reaches outside greenhouse by backwind tube through the sidewall in described greenhouse;

New wind blower fan, be positioned at described greenhouse outside, its one end is fresh wind port, and the other end is air outlet and extend in greenhouse by ajutage through the sidewall in described greenhouse;

Drying bed, is arranged on described inside greenhouse, described drying bed is provided with and turns over mud machine;

Control centre, is connected with described return air fan and new wind blower fan;

Greenhouse type combined solar energy heat pump drying device also comprises source pump, and described source pump comprises:

Condenser, is positioned at described greenhouse, is arranged on described ajutage, and its one end is described air outlet;

Evaporimeter, is positioned at outside described greenhouse, is connected between described backwind tube and ajutage by evaporation tube, and described evaporimeter is connected with condenser by two loops; Described evaporimeter is provided with the second air-valve in the evaporation tube of exhaust outlet, and described evaporimeter is provided with the 4th air-valve in the evaporation tube of new wind blower fan, and described second air-valve is all connected with control centre with the 4th air-valve; One end near exhaust outlet in described backwind tube is provided with the first air-valve, and the one end near new wind blower fan in described ajutage is provided with the 3rd air-valve, and described first air-valve is all connected with control centre with the 3rd air-valve;

Expansion valve and compressor, be connected with described control centre, lays respectively in two loops that described evaporimeter is connected with condenser;

Heat exchanger, is connected between return air fan and evaporimeter by described backwind tube, is connected between evaporimeter and condenser by described ajutage.

2. greenhouse type combined solar energy heat pump drying device as claimed in claim 1, its feature in, described greenhouse is provided with feeding gate and discharge door.

3. a drying means for the greenhouse type combined solar energy heat pump drying device according to any one of claim 1-2, is characterized in that, comprise the following steps:

Step S1, control centre detect solar energy intensity and whether are greater than the first setting value meeting greenhouse dehumidifying needs, are perform step S2, otherwise judge solar energy intensity whether between the first setting value and the second setting value, are perform step S3;

Step S2, control centre control closedown second air-valve and the 4th air-valve, and judge whether to reach default release, are perform step S21;

Step S21, open the first air-valve and the 3rd air-valve, the air in greenhouse to be pumped by return air fan by return air inlet and is discharged through backwind tube and exhaust outlet, and the air outside greenhouse to be pumped by new wind blower fan by fresh wind port and sent in greenhouse through ajutage and air outlet;

Step S3, control centre judge whether to reach default release, control the first air-valve and all open to the 4th air-valve, the aperture of each air-valve is controlled according to solar energy Strength co-mputation by control centre, determine the unlatching of source pump, and determine return air, the flow direction of air-supply and distribution, realize indoor heat demand balance between supply and demand.

4. greenhouse type combined solar energy heat pump drying means as claimed in claim 3, it is characterized in that, described step S1 also comprises:

If control centre monitors solar energy intensity lower than the second setting value, then perform step S4.

5. greenhouse type combined solar energy heat pump drying means as claimed in claim 4, is characterized in that, also comprise:

Step S4, described control centre control closedown first air-valve and the 3rd air-valve, open the second air-valve and the 4th air-valve, and control to open source pump: absorbed by the heat pump fluid of evaporimeter from the heat of the damp-heat air in greenhouse in evaporimeter, hydrogenesis in damp-heat air is also discharged, the heat pump fluid of described evaporimeter enters into compressor and is further heated pressurization, heat pump fluid after heating pressurization enters into condenser, carries out heat exchange with the heat pump fluid in condenser; Air dehumidified in evaporimeter also enters into condenser, heat exchange is carried out with the heat pump fluid of condenser, the heat pump fluid temperature of condenser reduces, heat pump fluid after temperature reduces is through expansion valve decrease temperature and pressure further, enter evaporimeter and carry out the heat that next round absorbs damp-heat air, the hot-air after condenser heat exchange is sent in greenhouse by air outlet.

6. greenhouse type combined solar energy heat pump drying means as claimed in claim 5, is characterized in that, also comprise:

Preheater, heat exchange is carried out with the air of lowering the temperature through evaporator from the damp-heat air in the greenhouse that return air fan is discharged.