CN204811761U - Open multistage heat pump drying equipment of closed circulation - Google Patents

Abstract

An open-close cycle multi-stage heat pump drying equipment includes a heat pump system, a grain drying tower and open-close cycle cold and hot air pipes. The heat pump system is connected with the grain drying tower through the hot air duct, the hot air intake hood, the cold air duct, and the cold air intake hood. The induced draft fan is connected with the grain drying tower through the waste gas pipeline and the dry waste gas exhaust hood. The inside of the drying tower is an angular tubular air duct, which can form a co-current drying or mixed-flow drying process according to different arrangements. There is a slow section between the exhaust angular tube and the intake angular tube, which can be formed according to different drying processes. Multi-stage co-current or mixed-flow drying process, with a counter-current cooling section in the last drying section. The heat pump system has the functions of heat absorption, dehumidification and heating. The throttling device of the heat pump system can realize constant capacity and variable capacity adjustment, and is equipped with a regenerator. The control system can realize variable temperature, variable capacity and variable parameter control functions, and realize the control of the complex drying process.

Description

An open-close cycle multi-stage heat pump drying equipment

technical field

The invention relates to the fields of heat pump energy-saving drying technology and grain drying technology, in particular to an open-close cycle multi-stage heat pump drying equipment.

Background technique

Compared with coal-fired or oil-fired heat exchangers, heat pump drying equipment has technical advantages such as significant energy saving, no pollution, and parameter controllability. At present, a typical trend in the development of drying equipment technology is the organic combination of new high-efficiency clean heat sources and traditional drying devices to give full play to the advantages of new heat sources and traditional drying processes. In particular, the use of dehumidification functions of various heat pumps for waste heat recovery effectively improves energy-saving effects. .

Contents of the invention

The invention proposes an open-close cycle multi-stage heat pump drying equipment, which is a heat pump drying equipment organically combined with a drying device with a tower-type angular tube structure. There are two ways of closed cycle, especially when the closed cycle is used, the dehumidification function of the heat pump evaporator is used to recover the sensible heat and latent heat in the exhaust gas, and the energy saving effect is improved. In the drying process, according to the characteristics of specific grains, the drying operation can be carried out by combining two to eight stages of co-current or mixed-flow drying technology and counter-current cooling technology.

The specific content of the present invention:

An open-close cycle multi-stage heat pump drying equipment is characterized in that: the heat pump drying combined with the drying device of the angular tube structure is an open discharge of the exhaust gas of the separate heat pump drying or the closed cycle drying equipment combined with the heat pump dehumidification and drying, It includes a heat pump device, a drying tower with an angular tube structure and related hot air or exhaust gas pipelines, etc.; the open-close multi-stage heat pump drying equipment described is a tower dryer, and the dryers are as follows from left to right:

1 grain storage section, 2 primary air intake section, 3 primary exhaust section, 4 secondary air intake section, 5 secondary exhaust section, 6 tertiary air intake section, 7 double exhaust section, 8 cooling section, 9 Grain discharge section, 10 Grain discharge auger, 11 Elevator, 12 Circulating air pipe, 13 Heat pump system, 14 Hot air pipe, 15 Counterflow cooling pipe, 16 Return air electric damper, 17 Counterflow cooling electric damper, 18 Hot air inlet Gas hood, 19 exhaust gas exhaust hood

The heat pump system is composed of a compressor, a main condenser, a dehumidification evaporator, an endothermic evaporator, a regenerator, a thermal expansion valve, an electronic expansion valve, a four-way reversing valve, a liquid storage tank, and a gas-liquid separator. and so on.

The heat-absorbing evaporator of the heat pump system mainly absorbs heat from the ambient air. The functions of the dehumidification evaporator include dehumidification of the ambient air, dehumidification of the circulating dry exhaust gas, and absorption of sensible heat and latent heat in the exhaust gas. After dehumidification, the dry medium air becomes high-temperature and low-humidity air through heat exchange with the main condenser, enters the hot air pipeline 14, enters the drying tower through the multi-stage air intake section of the drying tower, and forms when the grain flow direction is the same as The downstream drying process can form a circulating drying process when changing the arrangement structure of the angular tubes, so as to meet the drying requirements of different materials. By exchanging heat and mass with the grain, the water vapor evaporated from the grain is taken away, and discharged into the exhaust hood through the angular pipe of the exhaust section, and then discharged into the atmosphere through the fan or passed through the closed circulation pipeline again. Enter the heat pump system, and enter the next cycle.

In the final stage of drying, when the final moisture content of the drying is close to being reached, the countercurrent of the double-row exhaust section is used to further fine-tune the drying, dehydration and cooling, and when the moisture content requirements are met, the grain is discharged. If there is a large difference between the measured moisture content and the final moisture content, the grain will enter the drying tower again through the elevator to form a re-drying process until the moisture content of the grain reaches the standard.

Features and advantages of the present invention:

An open-close cycle multi-stage heat pump drying equipment, which can realize multiple drying modes: 1) The waste gas open discharge mode is suitable for grains such as rice containing tiny glume-like objects, and prevents the glumes from being damaged by the waste gas closed cycle process. Plugged heat exchanger. 2) It is suitable for grains with high cleanliness. The exhaust gas can realize closed circulation, and absorb sensible heat and latent heat through dehumidification and evaporation to improve energy saving effect. In addition, the regenerator has the function of reducing invalid cooling consumption and improving dehumidification performance; the versatility of the equipment High, suitable for drying and dehydration of bulk food crops such as rice, corn, wheat, etc., and also suitable for drying miscellaneous grains and various vegetable seeds.

Description of drawings

Figure 1 is a diagram of an open-close cycle multi-stage heat pump drying equipment

1 grain storage section, 2 primary air intake section, 3 primary exhaust section, 4 secondary air intake section, 5 secondary exhaust section, 6 tertiary air intake section, 7 double exhaust section, 8 cooling section, 9 Grain discharge section, 10 Grain discharge auger, 11 Elevator, 12 Circulating air pipe, 13 Heat pump system, 14 Hot air pipe, 15 Counterflow cooling pipe, 16 Return air electric damper, 17 Counterflow cooling electric damper, 18 Hot air inlet Gas hood, 19 exhaust gas exhaust hood

Detailed ways

An open-close cycle multi-stage heat pump drying equipment is a co-current or mixed-flow drying equipment combined with a heat pump dehumidification drying and a drying tower with an angular tube structure. It includes a heat pump drying system, a drying tower with an angular tube structure and Hot air pipes, exhaust gas discharge and closed circulation pipes, etc.;

One of the open and closed cycle multi-stage heat pump drying equipment is as follows from top to bottom:

1 grain storage section, 2 primary air intake section, 3 primary exhaust section, 4 secondary air intake section, 5 secondary exhaust section, 6 tertiary air intake section, 7 double exhaust section, 8 cooling section, 9 Grain discharge section, 10 Grain discharge auger, 11 Elevator, 12 Circulating air pipe, 13 Heat pump system, 14 Hot air pipe, 15 Counterflow cooling pipe, 16 Return air electric damper, 17 Counterflow cooling electric damper, 18 Hot air inlet Gas hood, 19 exhaust gas exhaust hood

The working process of an open-close cycle multi-stage heat pump drying equipment: in the initial stage, the grain passes through the hoist 11 and enters the drying tower with an angular tube structure. The heat-absorbing evaporator of the heat pump system 13 mainly absorbs heat from the ambient air, and the function of the dehumidifying evaporator includes dehumidifying the ambient air, dehumidifying the circulating dry waste gas, and absorbing sensible heat and latent heat in the waste gas. After dehumidification, the dry medium air becomes high-temperature and low-humidity air through heat exchange with the main condenser, and enters the primary air intake section 2 and secondary air intake section 4 of the drying tower through the hot air pipe 14 and the hot air intake hood 18 , three-stage air intake section 6 and other multi-stage air intake, when the hot air and grain flow in the same direction, a downstream drying process is formed. When the arrangement of the angular tubes is changed, a circular flow drying process can be formed to meet the drying requirements of different materials. Through the heat and mass exchange with the grain, the water vapor evaporated from the grain is taken away, and exhausted to the exhaust gas through the angular pipes of the first exhaust section 3 and the second exhaust section 57 of the double exhaust section. Inside the cover 19, it is discharged into the atmosphere through the blower fan, and the return air electric damper 16 is opened when a closed cycle is required, and the waste gas enters the heat pump system again through the circulating air pipeline 12, and enters the next cycle.

In the final stage of drying, when the final moisture content of the drying is reached, the countercurrent cooling electric air valve 17 is opened, and the low-temperature air generated by the heat pump system enters the double exhaust section 7 through the countercurrent cooling pipe 15, and the drying, dehydration and temperature reduction are further fine-tuned by countercurrent cooling , when the moisture content requirement is reached, the grain is discharged through the grain discharge auger 10. If there is a large difference between the measured moisture content and the final moisture content, the grain enters the drying tower again through the hoist 11 to form a re-drying process until the grain moisture content reaches the standard.

Claims (1)

1. An open and closed cycle multi-stage heat pump drying equipment, characterized in that: heat pump drying combined with an angular tube structure drying device combined with open discharge of exhaust gas from heat pump drying or closed cycle drying combined with heat pump dehumidification and drying Equipment, which includes a heat pump device, a drying tower with an angular tube structure, and related hot air or exhaust gas pipelines; the open-close multi-stage heat pump drying equipment described is a tower dryer, and the dryers are in order from left to right: (1) grain storage section, (2) primary air intake section, (3) primary exhaust section, (4) secondary air intake section, (5) secondary exhaust section, (6) tertiary air intake section section, (7) double exhaust section, (8) cooling section, (9) grain discharge section, (10) grain discharge auger, (11) elevator, (12) circulating air duct, (13) heat pump system, (14) hot blast duct, (15) countercurrent cooling duct, (16) return air electric air valve, (17) countercurrent cooling electric air valve, (18) hot air intake cover, (19) exhaust gas exhaust cover.