CN201561564U - A direct-fired air source absorption heat pump water heater - Google Patents

Abstract

A direct-fired air source absorption heat pump water heater belongs to the field of HVAC equipment. The technical feature of the utility model is that a defrosting branch is connected between the refrigerant steam outlet and the evaporator inlet. The defrosting branch is connected in parallel with the refrigerant liquid pipeline where the condenser and the throttling device are located. A regulating valve is set on the frost branch; the evaporator adopts an air-cooled evaporator. The utility model uses an air-cooled evaporator to directly obtain heat from the air, and sends tap water or low-temperature hot water returned from the user end to the absorber and condenser of the absorption heat pump unit in sequence to produce hot water with a higher temperature. This method has higher primary energy utilization efficiency and exergy efficiency than boiler heating directly burning fossil fuels, and solves the defrosting problem in the heat extraction process of the air-cooled evaporator through the defrosting bypass.

Description

A direct-fired air source absorption heat pump water heater

technical field

The utility model relates to a heat pump water heating device, which belongs to the technical field of HVAC equipment, and is especially suitable for preparing hot water for heating and domestic use in the HVAC system.

Background technique

With the rapid development of my country's economy and the improvement of people's living standards and health awareness, people's demand for domestic hot water is increasing, and their requirements for heating comfort are getting higher and higher. The consumption of domestic hot water and heating hot water is increasing. Constantly increasing. Especially in terms of heating and hot water, the scope of my country's heating area is getting larger and larger, and has expanded from the traditional north of the Yellow River to the south of the Yangtze River, and even in Guangxi and Fujian, heating has begun in winter. Rural areas with better living conditions are gradually eliminating the method of directly burning coal to prepare hot water for heating.

At present, most of my country's heating and hot water use coal-fired, gas-fired or oil-fired boilers, and will maintain this method for a long period of time. The common mode of hot water boiler heating is to exchange heat between the generated steam and the water on the secondary side through a heat exchanger, so that the water temperature is raised and then supplied to the user; or directly supply the generated hot water to the user. There are three deficiencies in this mode of producing hot water: (1) the efficiency of primary energy use is low: the efficiency of coal-fired boilers is usually between 40% and 70%, and the efficiency of natural gas and oil-fired boilers is about 70% to 90%; Utilize low-grade heat sources available in nature; (3) The efficiency of the boiler device hardly changes when producing hot water at different temperatures, and even the efficiency of producing low-temperature hot water also slightly decreases.

According to the second law of thermodynamics, the lower the temperature of the hot water produced, the higher the efficiency of the hot water production device should be. However, the temperature of hot water required for heating and domestic hot water in our life is usually not very high, about 30-60°C, so can we propose a hot water device whose efficiency of producing hot water is much higher than the current one? boiler, and its efficiency is higher when producing hot water at a lower temperature?

In addition, the current absorption heat pump water heating device is based on absorption heat pump technology, which effectively uses low-grade energy such as industrial wastewater and waste gas to produce hot water. However, in the current absorption heat pump water heating device, the evaporators are all water-cooled evaporators, which cannot extract heat from the air, so that a large amount of free low-grade heat energy in the air has not been effectively utilized.

The utility model proposes a direct-fired air source absorption heat pump water heating device. The device uses an air-cooled evaporator to directly obtain heat from the air to produce hot water. Defrost problem outside the device.

Utility model content

The utility model proposes a technical scheme of a direct-fired air source absorption heat pump water heating device, which will provide heat sources for HVAC systems and domestic hot water. The difference in energy consumption can improve the utilization rate of primary energy.

The technical scheme of the utility model is:

A direct-fired air source absorption heat pump water heating device, the device includes an absorption heat pump unit, a water inlet pipe and a water outlet pipe, and the absorption heat pump unit is composed of a direct-fired generator, a condenser, a throttling device, an evaporation The refrigerant steam outlet of the direct-fired generator and the refrigerant side inlet of the condenser pass through the first refrigerant The refrigerant side outlet of the condenser is connected with the throttling device on the refrigerant liquid pipe, the refrigerant inlet of the absorber is connected with the second refrigerant steam pipe, the concentrated solution inlet of the absorber is connected to the solution throttling The flow valve is connected through the concentrated solution pipe, and the dilute solution outlet of the absorber is connected with the solution pump through the dilute solution pipe. The defrosting branch is connected in parallel with the refrigerant liquid pipeline where the condenser and throttling device are located, and a regulating valve is set on the defrosting branch, and the evaporator adopts an air-cooled evaporator. Wherein, the device may be a direct-fired single-effect absorption heat pump unit or a direct-fired double-effect absorption heat pump unit.

Adopting the above-mentioned technical scheme has the following significant advantages:

效率更高。而锅炉制热时，无论制取热水的温度高还是低，其能源利用效率基本不变。①The condenser and throttling device are bypassed through the defrosting branch to defrost the evaporator, which solves the problem of effective defrosting in the heat extraction process of the air-cooled evaporator. ② Make full use of the outdoor air heat source and have a higher primary energy utilization rate than boilers. ③ When producing hot water with a lower temperature, the primary energy utilization efficiency and

higher efficiency. When the boiler is heating, no matter whether the temperature of hot water is high or low, its energy utilization efficiency basically remains the same.

Description of drawings

Fig. 1 is a schematic structural view of a direct-fired air source absorption heat pump water heating device provided by the utility model.

Fig. 2 is a schematic diagram of the operation of a direct-fired air source absorption heat pump water heater provided by the utility model in the hot water supply mode.

Fig. 3 is a schematic diagram of the operation of a direct-fired air source absorption heat pump water heater provided by the utility model in the defrosting mode.

Among them: 1-direct combustion generator; 2-absorber; 3-condenser; 4-air-cooled evaporator; 5-absorption heat pump unit; 6-solution heat exchanger; 7-throttling device; 8-fuel Chamber; 9-solution pump; 10-solution throttle valve; 11-defrosting branch; 12-dilute solution pipe; 13-concentrated solution pipe; 14-first refrigerant steam pipeline; 15-refrigerant liquid pipeline ; 16-second refrigerant steam pipeline; 17-hot water pipeline; 18-regulating valve.

Detailed ways

Fig. 1 is a schematic structural view of a direct-fired air source absorption heat pump water heating device provided by the utility model. The device includes an absorption heat pump unit, a water inlet pipe and an outlet pipe. The absorption heat pump unit consists of a direct-fired generator 1, a condenser 3, a throttling device 7, an evaporator, an absorber 2, and a solution heat exchanger 6. , a solution pump 9, and a solution throttle valve 10 arranged on a concentrated solution pipe 13. The refrigerant vapor outlet of the direct-fired generator 1 and the refrigerant side inlet of the condenser 3 pass through the first refrigerant vapor pipeline 14 The refrigerant side outlet of the condenser 3 and the throttling device 7 are jointly connected to the refrigerant liquid pipeline 15, the refrigerant inlet of the absorber 2 is connected to the second refrigerant vapor pipeline 16, and the concentrated solution of the absorber 2 The inlet is connected to the solution throttle valve 10 through the concentrated solution pipe 13, the dilute solution outlet of the absorber 2 is connected to the solution pump 9 through the dilute solution pipe 12, and the refrigerant vapor outlet of the direct-fired generator 1 is connected to the evaporator inlet. A defrosting branch 11 is provided. The defrosting branch 11 is connected in parallel with the refrigerant liquid pipeline 15 where the condenser 3 and the throttling device 7 are located, and a regulating valve 18 is set on the defrosting branch 11. The evaporator Adopt air-cooled evaporator 4.

The utility model will be further described below in conjunction with the accompanying drawings, where the dotted line in the figure is the current non-working branch.

1. Hot water heating mode

Fig. 2 is a schematic structural diagram of a direct-fired air source absorption heat pump water heating device provided by the utility model when supplying hot water.

Close the regulating valve 18, the solution of the direct-fired generator 1 is heated, the refrigerant evaporates and escapes, the concentration of the solution increases, and the concentrated solution passes through the solution heat exchanger 6 and the solution throttle valve 10 to cool down and throttle, and then enters the absorber 2. After absorbing the refrigerant vapor from the air-cooled evaporator 4, the concentration of the solution decreases, and then the solution pump 9 passes through the solution heat exchanger 6 to exchange heat with the concentrated solution and then returns to the direct-fired generator 1; The solution in the combustion-type generator 1 is heated, and the refrigerant evaporates and escapes, and condenses into a refrigerant liquid through the first refrigerant vapor pipeline 14 to the condenser 3, and then passes through the throttling device 7 on the refrigerant liquid pipeline 15 to reduce pressure. After flowing, it enters the air-cooled evaporator 4 to absorb the heat in the air and evaporates, and then enters the absorber 2 to be absorbed by the solution to release heat; the return water on the user side passes through the solution in the absorber 2 and the condenser 3 to release heat. After heating for the first time, it is supplied to users.

During this operation, the air-cooled evaporator absorbs the free heat in the air, which improves the primary energy utilization efficiency and saves energy compared to simply burning fossil fuels.

2. Defrost mode

Because the air-cooled evaporator 4 is in the process of absorbing the external air heat source, when the external ambient temperature is too low, it is easy to form frost on the outside of the evaporator, resulting in that the heat exchange process cannot be carried out normally, thereby affecting the normal operation of the unit.

Fig. 3 is a schematic diagram of the operation of a direct-fired air source absorption heat pump water heater provided by the utility model in the defrosting mode.

When frost forms on the outside of the air-cooled evaporator 4 , the regulating valve 18 is opened, and the condenser 3 and the throttling device 7 are bypassed by the defrosting branch 11 . The solution in the direct-fired generator 1 is heated, the refrigerant evaporates and escapes, the concentration of the solution increases, and the concentrated solution enters the absorber 2 after passing through the solution heat exchanger 6 and the solution throttling valve 10 to cool down and throttling. After the condensed liquid in the air-cooled evaporator 4, the concentration of the solution increases, and then the solution pump 9 passes through the solution heat exchanger 6 to exchange heat with the concentrated solution and then returns to the direct-fired generator 1; the direct-fired generator 1 When the solution is heated, the refrigerant evaporates and escapes, passes through the defrosting branch 11 to the air-cooled evaporator 4 to condense into a refrigerant liquid, and then enters the absorber 2; the air-cooled evaporator 4 absorbs the heat on the refrigerant vapor, and the frost Melted by heat, thereby reaching the purpose of defrosting the air-cooled evaporator 4 . Thereafter, the regulating valve 18 is closed again, and the device switches back to the heating mode to supply hot water to the user.

Claims (2)

1. A direct-fired air source absorption heat pump water heater, the device comprises an absorption heat pump unit (5), a water inlet pipe and a water outlet pipe, and the absorption heat pump unit (5) consists of a direct-fired generator ( 1), condenser (3), throttling device (7), evaporator, absorber (2), solution heat exchanger (6), solution pump (9), solution section arranged in concentrated solution pipe (13) flow valve (10), the refrigerant vapor outlet of the direct-fired generator (1) is connected to the refrigerant side inlet of the condenser (3) through the first refrigerant vapor pipeline (14), and the condenser (3 ) and the throttling device (7) are connected to the refrigerant liquid pipeline (15), the refrigerant inlet of the absorber (2) is connected to the second refrigerant vapor pipeline (16), and the absorber The concentrated solution inlet of (2) is connected to the solution throttle valve (10) through the concentrated solution pipe (13), and the dilute solution outlet of the absorber (2) is connected to the solution pump (9) through the dilute solution pipe (12). In that: a defrosting branch (11) is connected between the refrigerant steam outlet of the direct-fired generator (1) and the evaporator inlet, and the defrosting branch (11) is connected to the condenser (3) and the throttle The refrigerant liquid pipeline (15) where the flow device (7) is located is connected in parallel, and a regulating valve (18) is set on the defrosting branch (11), and the evaporator adopts an air-cooled evaporator (4). 2. A direct-fired air source absorption heat pump water heater according to claim 1, characterized in that: the direct-fired absorption heat pump unit (5) is a direct-fired single-effect absorption heat pump unit Or direct-fired double-effect absorption heat pump unit.

Images