Box-type high-temperature air source heat pump hot air unit for drying cereals

Abstract

The utility model discloses a box-type high-temperature air source heat pump hot air unit for drying cereals, which belongs to the technical field of drying devices and comprises a heat pump box body, an air return port and an air supply port, and the air return port and the air supply port are arranged on two sides of the heat pump box body. An evaporator is arranged at the rear end of the filter, a compressor assembly is arranged at the rear end of the evaporator, a condenser is arranged at the rear end of the compressor assembly, the rear end of the condenser is connected with the inlet end of the air supply outlet, and an auxiliary electric heater is arranged at the inlet end of the condenser. According to the device, the large compression ratio of traditional single-stage heating is reduced through stage-by-stage heating, safe and reliable operation of the compressor is guaranteed, the heating energy efficiency ratio of the whole high-temperature heat pump is increased, integral type or split type installation can be conducted according to site conditions, cost is reduced, space is saved, and the device is suitable for being used under the high-temperature air supply drying working condition.

Description

Technical Field

[0001] The utility model relates to the technical field of drying devices, in particular to a box-type high-temperature air source heat pump hot air unit for drying grains. Background Art

[0002] The air source heat pump hot air unit has the characteristics of high efficiency, energy saving, environmental protection, high dehydration rate and hygiene and safety. It is a green, gentle and close to nature drying method. It can retain the nutrients of the material to the maximum extent without destroying its original structure. It has been widely used in the mechanical drying of common crops such as rice and wheat.

[0003] During the operation of the air source heat pump unit, it is often limited by the physical properties of the refrigerant and the application characteristics of the high-temperature compressor. The energy efficiency ratio is low under high-temperature conditions, which makes the high-temperature (high supply air temperature) air source heat pump fail to be effectively promoted. It is rarely used in the drying of heat sources such as corn and feed that require high-temperature hot air. In addition, traditional heating generally adopts single-stage heating, which has the problem of large single-stage compression ratio, resulting in a large workload for the compressor and a hidden danger to the safe operation of the compressor. Utility Model Content

[0004] The purpose of the utility model is to overcome the defects in the prior art and provide a box-type high-temperature air source heat pump hot air unit for drying grains. The high compression ratio of traditional single-stage heating is reduced by step-by-step heating, thereby ensuring the safe and reliable operation of the compressor, improving the heating energy efficiency of the high-temperature heat pump unit, and expanding the application range of the high-temperature heat pump unit.

[0005] The purpose of the utility model is achieved as follows: a box-type high-temperature air source heat pump hot air unit for drying grains, comprising a heat pump box body and a return air port and an air supply port arranged on both sides of the heat pump box body, an electric control box and an air filter assembly are arranged in the heat pump box body, the air filter assembly comprises a filter arranged at the rear end of the return air port, an evaporator is arranged at the rear end of the filter, a compressor assembly is arranged at the rear end of the evaporator, a condenser is arranged at the rear end of the compressor assembly, the rear end of the condenser is connected to the inlet end of the air supply port, and an auxiliary electric heater is also arranged at the inlet end of the condenser.

[0006] When the utility model is working, by setting a multi-stage condenser and evaporator, heat is absorbed on the source side of the heat pump for heat recovery, and the low-temperature fresh air is heated step by step on the use side to heat the low-temperature fresh air step by step to high-temperature hot air for drying. The medium-temperature hot and humid air discharged by the drying device is filtered through dust removal and then introduced to the heat pump evaporator inlet through the insulation air duct. After heat and moisture exchange in the evaporator, the cold air is discharged after absorbing excess heat to reduce moisture. Through full heat recovery, the evaporation temperature on the source side is not affected by the outdoor low temperature environment, and the lowest evaporation temperature is also higher than the freezing point, eliminating the problem of the whole machine heating capacity and heating energy efficiency ratio decreased due to frost and defrost of the evaporator caused by the outdoor low temperature environment. Compared with the prior art, the device reduces the large compression ratio of traditional single-stage heating under a wide range of temperature rise by step-by-step heating, ensures the safe and reliable operation of the compressor, and improves the heating energy efficiency ratio of each level of the high-temperature heat pump; the device has a compact structure and can be installed as a whole or in a split manner according to the on-site conditions, which can minimize the engineering installation cost and save space.

[0007] Furthermore, the condenser includes a first-stage condenser, a second-stage condenser, a third-stage condenser and a fourth-stage condenser which are arranged in sequence, and the evaporator includes a fourth-stage evaporator, a third-stage evaporator, a second-stage evaporator and a first-stage evaporator which are arranged in sequence, the inlet end of the first-stage condenser is connected to the outdoor fresh air channel, the outlet end of the fourth-stage condenser discharges high-temperature dry hot air for heat pump drying, the inlet end of the fourth-stage evaporator is connected to the medium-temperature hot and wet return air channel, and the outlet end of the first-stage evaporator discharges cold air to the outside through an exhaust fan.

[0008] Furthermore, a first-stage throttle valve and a first-stage compressor are provided on the pipeline between the first-stage condenser and the first-stage evaporator, a second-stage throttle valve and a second-stage compressor are provided on the pipeline between the second-stage condenser and the second-stage evaporator, a third-stage throttle valve and a third-stage compressor are provided on the pipeline between the third-stage condenser and the third-stage evaporator, and a fourth-stage throttle valve and a fourth-stage compressor are provided on the pipeline between the fourth-stage condenser and the fourth-stage evaporator.

[0009] Furthermore, an exhaust fan is provided above the heat pump housing, and a plurality of the exhaust fans are provided, and an exhaust port of the exhaust fan is arranged toward the outside of the heat pump housing.

[0010] Furthermore, the compressor assemblies are provided in a plurality of groups along the width direction of the heat pump housing, and fresh air inlets are correspondingly provided on the heat pump housing opposite to the compressor assemblies.

[0011] Furthermore, a rain cover is provided at the inlet end of the fresh air outlet.

[0012] Furthermore, the filter comprises a primary filter and a medium filter, and the medium filter is arranged at the rear end of the primary filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front view schematic diagram of the overall structure of the heat pump unit of the utility model.

[0014] Figure 2 It is a top view schematic diagram of the overall structure of the heat pump unit of the utility model.

[0015] Figure 3 It is a front view schematic diagram of the separate structure of the heat pump unit of the utility model.

[0016] Figure 4 It is a top view schematic diagram of the separate structure of the heat pump unit of the utility model.

[0017] Figure 5 This is a system schematic diagram of the heat pump unit of the utility model.

[0018] Among them, 1 is the return air outlet, 2 is the primary filter, 3 is the medium filter, 4 is the evaporator, 5 is the exhaust fan, 6 is the electric control box, 7 is the compressor assembly, 8 is the heat pump box, 9 is the auxiliary electric heater, 10 is the condenser, 11 is the air outlet, and 12 is the rain cover. DETAILED DESCRIPTION Example

[0019] like Figure 1 , 2 The box-type high-temperature air source heat pump hot air unit for drying grains shown in the figure includes an integral heat pump box body 8 and a return air port 1 and an air supply port 11 arranged on both sides of the heat pump box body 8. An electric control box 6 and an air filter assembly are arranged in the heat pump box body 8. The air filter assembly includes a filter arranged at the rear end of the return air port 1, an evaporator 4 is arranged at the rear end of the filter, a compressor assembly 7 is arranged at the rear end of the evaporator 4, a condenser 10 is arranged at the rear end of the compressor assembly 7, the rear end of the condenser 10 is connected to the inlet end of the air supply port 11, and an auxiliary electric heater 9 is also arranged at the inlet end of the condenser 10.

[0020] The condenser 10 includes a first-stage condenser, a second-stage condenser, a third-stage condenser and a fourth-stage condenser which are arranged in sequence, and the evaporator 4 includes a fourth-stage evaporator, a third-stage evaporator, a second-stage evaporator and a first-stage evaporator which are arranged in sequence. The inlet end of the first-stage condenser is connected to the outdoor fresh air channel, and the outlet end of the fourth-stage condenser discharges high-temperature dry hot air for heat pump drying. The inlet end of the fourth-stage evaporator is connected to the medium-temperature hot and wet return air channel, and the outlet end of the first-stage evaporator discharges cold air to the outside through the exhaust fan.

[0021] A first-stage throttle valve and a first-stage compressor are arranged on the pipeline between the first-stage condenser and the first-stage evaporator, a second-stage throttle valve and a second-stage compressor are arranged on the pipeline between the second-stage condenser and the second-stage evaporator, a third-stage throttle valve and a third-stage compressor are arranged on the pipeline between the third-stage condenser and the third-stage evaporator, and a fourth-stage throttle valve and a fourth-stage compressor are arranged on the pipeline between the fourth-stage condenser and the fourth-stage evaporator.

[0022] The heat pump housing 8 is provided with an exhaust fan 5 , and a plurality of exhaust fans 5 are provided. The exhaust ports of the exhaust fans 5 are arranged toward the outside of the heat pump housing 8 .

[0023] Several groups of compressor assemblies 7 are arranged along the width direction of the heat pump housing 8, and a fresh air inlet is correspondingly arranged on the heat pump housing 8 opposite to the compressor assemblies 7; a rain cover 12 is also arranged at the inlet end of the fresh air inlet.

[0024] The filter comprises a primary filter 2 and a medium filter 3 , wherein the medium filter 3 is arranged at the rear end of the primary filter 2 .

[0025] When the utility model is working, Figure 5 As shown, low-temperature and low-pressure refrigerant vapor enters the compressor through pipelines, is compressed and converted into high-temperature and high-pressure steam, and then enters the condenser through pipelines to exchange heat with the low-temperature fresh air entering from the outside. The generated high-temperature hot air is used for drying materials such as corn and feed. The compressors in this device include a first-stage compressor, a second-stage compressor, a third-stage compressor and a fourth-stage compressor. The low-temperature fresh air is heated to 120°C through step-by-step heating by the compressors. Within a large temperature rise range of more than 100 degrees, the heating energy efficiency ratios of each stage of the heat pump can reach approximately 5.8, 3.3, 2.9 and 2.1 respectively, and the comprehensive energy efficiency can still be as high as about 3.2. The medium-temperature hot and humid air discharged from the drying device passes through the primary filter 2 and the medium-efficiency filter 3 for dust removal and filtration, and is then led to the inlet of the heat pump evaporator 4 through the insulated air duct. After heat and moisture exchange in the evaporator 4, the cold air is discharged after absorbing excess heat and reducing moisture, thereby realizing full heat recovery of the heat pump unit. The evaporator 4 in this device includes a four-stage evaporator, a three-stage evaporator, a two-stage evaporator and a one-stage evaporator. The evaporator 4 absorbs heat energy in the return air, and full heat recovery also makes the evaporation temperature on the source side not affected by the outdoor low temperature environment, and the lowest temperature is also above the freezing point, which eliminates the problem of reduced heating capacity of the entire machine caused by frost and defrost of the evaporator of the air source heat pump due to the outdoor low temperature environment, thereby improving the heating energy efficiency ratio. Example

[0026] like Figure 3 , 4The box-type high-temperature air source heat pump hot air unit for drying grains shown in the figure comprises a split heat pump box 8, which comprises two parts, wherein a return air port 1 and an exhaust fan 5 are respectively arranged at both ends of one heat pump box 8, a primary filter 2 is arranged at the rear end of the return air port 1 in the heat pump box 8, a medium filter 3 is arranged at the rear end of the primary filter 2, an evaporator 4 is arranged at the rear end of the medium filter 3, and the outlet end of the evaporator 4 is connected to the exhaust fan 5. The medium-temperature hot and humid air discharged from the drying device is connected to the return air port through a pipeline, and is introduced into the heat pump evaporator 4 for cooling after dust removal and filtration, and finally discharged through the exhaust fan 5; a fresh air port and an air supply port 11 are respectively arranged at both ends of the other heat pump box 8, an electric control box 6 and a compressor assembly 7 are arranged in the heat pump box 8, a condenser 10 is arranged at the rear end of the compressor assembly 7, the rear end of the condenser 10 is connected to the air supply port 11, and an auxiliary electric heater 9 is also arranged at the front end of the condenser 10. When working, the device reduces the large compression ratio of traditional single-stage heating through step-by-step heating over a large temperature rise range, ensures safe and reliable operation of the compressor, and improves the heating energy efficiency of each stage of the high-temperature heat pump; in addition, the device has a compact structure and can be installed as a whole or in a split manner according to the site conditions, which can minimize the project installation cost, save floor space, and is suitable for use in different environmental conditions.

[0027] The present utility model is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present utility model, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present utility model.

Claims

1. A box-type high-temperature air source heat pump hot air unit for drying grains, comprising a heat pump box body and a return air inlet and an air supply inlet arranged on both sides of the heat pump box body, characterized in that: An electric control box and an air filter assembly are provided in the heat pump housing, the air filter assembly includes a filter arranged at the rear end of the return air outlet, an evaporator is provided at the rear end of the filter, a compressor assembly is provided at the rear end of the evaporator, a condenser is provided at the rear end of the compressor assembly, the rear end of the condenser is connected to the inlet end of the air supply outlet, and an auxiliary electric heater is also provided at the inlet end of the condenser.

2. A box-type high-temperature air source heat pump hot air unit for drying grains according to claim 1, characterized in that: The condenser includes a first-stage condenser, a second-stage condenser, a third-stage condenser and a fourth-stage condenser which are arranged in sequence, and the evaporator includes a fourth-stage evaporator, a third-stage evaporator, a second-stage evaporator and a first-stage evaporator which are arranged in sequence. The inlet end of the first-stage condenser is connected to an outdoor fresh air channel, and the outlet end of the fourth-stage condenser discharges high-temperature dry hot air for heat pump drying. The inlet end of the fourth-stage evaporator is connected to a medium-temperature hot and wet return air channel, and the outlet end of the first-stage evaporator discharges cold air to the outside through an exhaust fan.

3. A box-type high-temperature air source heat pump hot air unit for drying grains according to claim 2, characterized in that: A first-stage throttle valve and a first-stage compressor are provided on the pipeline between the first-stage condenser and the first-stage evaporator, a second-stage throttle valve and a second-stage compressor are provided on the pipeline between the second-stage condenser and the second-stage evaporator, a third-stage throttle valve and a third-stage compressor are provided on the pipeline between the third-stage condenser and the third-stage evaporator, and a fourth-stage throttle valve and a fourth-stage compressor are provided on the pipeline between the fourth-stage condenser and the fourth-stage evaporator.

4. A box-type high-temperature air source heat pump hot air unit for drying grains according to claim 1, characterized in that: An exhaust fan is arranged above the heat pump housing, and a plurality of the exhaust fans are arranged, and an exhaust port of the exhaust fan is arranged toward the outside of the heat pump housing.

5. The box-type high-temperature air source heat pump hot air unit for drying grains according to claim 1, characterized in that: The compressor components are arranged in a plurality of groups along the width direction of the heat pump housing, and the heat pump housing opposite to the compressor components is provided with corresponding fresh air inlets.

6. A box-type high-temperature air source heat pump hot air unit for drying grains according to claim 5, characterized in that: A rain cover is also provided at the inlet end of the fresh air outlet.

7. A box-type high-temperature air source heat pump hot air unit for drying grains according to claim 1, characterized in that: The filter comprises a primary filter and a medium filter, and the medium filter is arranged at the rear end of the primary filter.

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