CN103884097A - Semi-open and heat-returning type air compression circulation heat pump water heater - Google Patents

Abstract

The invention relates to a heat pump water heater of a semi-open heat recovery type air compression cycle, comprising an air compressor, a heating water tank, a regenerator and an air expander; the air compressor communicates with the inlet end of the heating water tank, and the regenerator The air outlet of the water tank is connected, the air outlet of the regenerator is directly connected to the external environment, the air expander and the regenerator are connected to form a circulation loop, and the air expander and the air compressor are connected through a transmission coupling. Compared with the prior art, the present invention is designed based on the basic principle of the reverse Brayton cycle. The heat pump unit absorbs heat from the ambient air and transfers it to high-temperature water through the process of compression, heat release, expansion and heat absorption. The heat pump directly uses air as the circulating working medium, which is harmless, non-polluting, and has no production cost. It can adopt a non-closed structure during use. The circulating working medium in the low-temperature heat exchanger can be directly obtained from the environment without considering the working medium. Leakage, no frosting problem under low temperature conditions.

Description

A heat pump water heater with a semi-open heat recovery type air compression cycle

technical field

The invention relates to a heat pump water heater, in particular to a heat pump water heater of a semi-open heat recovery type air compression cycle.

Background technique

The heat pump water heaters currently used in the market are mainly vapor compression heat pump water heaters. This type of water heater uses the reverse Carnot cycle principle to transfer heat from a low-temperature environment to high-temperature water through a medium, and its structure must adopt a closed structure. . Due to its fully enclosed structure, the vapor compression heat pump water heater has heat exchangers in both high and low temperature sections, and during the working process, the low temperature heat exchangers in contact with the environment are actually continuously absorbing heat and cooling. When the outside temperature is low, frosting will occur when the moisture in the air contacts the outdoor heat exchanger of the heat pump water heater. The efficiency of the heater drops significantly, seriously affecting the overall efficiency of the heat pump unit. In addition, when the ambient temperature becomes lower, generally speaking, the user's demand for heat is also greater, but at this time the heating capacity of the vapor compression heat pump becomes lower; However, when the temperature of the heat exchanger at the heating end is high, the heating capacity of the vapor compression heat pump water heater is at a relatively low level. It can be seen that there is a contradiction between heat supply and demand in the actual use of the vapor compression heat pump water heater. , which is a pair of irreconcilable contradictions caused by the characteristics of the vapor compression cycle. Although capacity adjustment methods such as compressor frequency conversion can be used to alleviate the contradiction between heat supply and demand, it increases the cost of the product and reduces the reliability of the product. The above two problems have hindered the development of vapor compression heat pump water heaters and their popularization and application in larger areas.

Contents of the invention

The object of the present invention is to provide a heat pump water heater with a semi-open heat recovery type air compression cycle in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A heat pump water heater with a semi-open heat recovery type air compression cycle, including an air compressor, a heating water tank, a regenerator, and an air expander; the air compressor communicates with the inlet end of the heating water tank, and the air compressor The environment sucks air and compresses it. The compressed air becomes high-temperature and high-pressure air. The high-temperature and high-pressure air enters the heating water tank to heat the water in the water tank: the regenerator communicates with the outlet end of the heating water tank, and the water coming out of the heating water tank The air enters the regenerator for heat exchange, and the outlet end of the regenerator is directly connected to the external environment. The air expander and the regenerator are connected to form a circulation loop, and the air expander and the air compressor are connected by a transmission Coupling connection, the air expander absorbs the heat of the air flowing out of the regenerator to do work, and transfers the work to the air compressor through the drive coupling to recover the expansion work.

The inlet of the air compressor communicates with the external environment through the air inlet pipe, the outlet of the air compressor is connected to the inlet of the heating water tank through the first connecting pipe, and the outlet of the heating water tank is connected to the return air through the second connecting pipe. The inlet end of the heat regenerator is connected, and the outlet end of the regenerator is connected to the external environment through the exhaust pipe. The low-pressure ends communicate with each other through the second circulation connecting pipe, forming a circulation loop between the regenerator and the air expander.

The air compressor is a turbo compressor, and the working medium air at the inlet of the air compressor is also directly extracted from the external environment.

The heating water tank is the main equipment for producing hot water, and the inside of the heating water tank is arranged with an air heat exchange channel for heat exchange with the water in the water tank, so as to heat the hot water through the air.

The regenerator is a single-phase fluid heat exchanger. The air with a higher temperature from the heating water tank enters the regenerator and exchanges heat with the gas from the air expander to reduce the temperature, which helps to reduce the temperature of the entire air. Cycle pressure ratio to improve system efficiency.

The air expander is a turbo type air expander, and the pressure drop process of the cycle is completed by using the turbo type air expander. During the process, the air entering the turbine will drive the turbine to rotate and do work, and this part of the work will be passed through The drive coupling transfers the energy to the air compressor to partly rotate the latter, and the energy recovery device helps to improve the overall performance of the unit; the air discharged from the low-pressure end of the air expander enters the regenerator for heat exchange and is directly discharged into the air.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) The heat pump water heater of the present invention does not use a low-temperature heat exchanger in the low-temperature heat absorption section but adopts an open design approach. Frosting problem of heat exchanger. At the same time, it can be proved by analyzing the characteristics of the air compression cycle heat pump that when the temperature of the external environment decreases or the temperature of the heating water increases, the heat that the heat pump water heater of the present invention can provide also increases, and the positive correlation between the two The relationship between heat supply and demand under different working conditions is balanced, which also solves the contradiction between heat supply and demand in the vapor compression heat pump water heater.

(2) The heat pump water heater of the present invention is designed based on the basic principle of the reverse Brayton cycle. The heat pump unit absorbs heat from the ambient air through the processes of compression, heat release, expansion, and heat absorption and transfers it to high-temperature water. The heat pump directly uses air as the circulating working medium, which is harmless, non-polluting, and has no production cost. It can adopt a non-closed structure during use. The circulating working medium in the low-temperature heat exchanger can be directly obtained from the environment without considering the working medium. Leakage, no frosting problem under low temperature conditions.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

In the figure, l is the air compressor, 2 is the first connecting pipe, 3 is the heating water tank, 4 is the second connecting pipe, 5 is the regenerator, 6 is the first circulation connecting pipe, 7 is the transmission coupling, 8 It is an air expander, 9 is a second circulation connecting pipe, 10 is an exhaust pipe, and 11 is an external environment.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

A heat pump water heater with a semi-open regenerative air compression cycle, as shown in Figure 1, includes an air compressor 1, a heating water tank 3, a regenerator 5 and an air expander 8: the inlet of the air compressor 1 passes through the intake pipe 12 communicates with the external environment 11, the outlet of the air compressor 1 is connected to the intake end of the heating water tank 3 through the first connecting pipe 2, the air compressor 1 inhales and compresses air from the external environment 11, and the compressed air becomes High-temperature and high-pressure air, the high-temperature and high-pressure air enters the heating water tank 3 to heat the water in the water tank; the outlet end of the heating water tank 3 is connected to the inlet end of the regenerator 5 through the second connecting pipe 4, and the air coming out of the heating water tank 3 enters Heat exchange is carried out in the regenerator 5, and the gas outlet end of the regenerator 5 is passed into the external environment 11 through the exhaust pipe 10, and the regenerator 5 and the high-pressure end of the air expander 8 are communicated through the first circulation connecting pipe 6, It communicates with the low-pressure end of the air expander 8 through the second circulation connecting pipe 9, forming a circulation loop between the regenerator 5 and the air expander 8, and the transmission coupling between the air expander 8 and the air compressor 1 The air expander 8 absorbs the heat of the air flowing out of the regenerator 5 to do work, and transmits the work to the air compressor 1 through the transmission coupling 7 to realize the recovery of the expansion work.

The air compressor 1 is a turbo compressor, and the working medium air at the inlet of the air compressor 1 is also directly extracted from the external environment.

The heating water tank 3 is the main equipment for producing hot water. The heating water tank 3 is equipped with an air heat exchange channel for heat exchange with the water in the water tank, so as to heat the hot water through the air.

The regenerator 5 is a single-phase fluid heat exchanger. The air with a higher temperature from the heating water tank 3 enters the regenerator 5 to exchange heat with the gas from the air expander 8, and the temperature is reduced, which helps to reduce the overall temperature. The pressure ratio of the air circulation thus improves the system efficiency.

The air expander 8 is a turbo-type air expander, which uses the turbo-type air expander to complete the pressure drop process of the cycle. During the process, the air passing through the turbine will drive the turbine to rotate and do work, and this part of the work will be passed through the transmission. The shaft device 7 transfers to the air compressor 1 to give the latter part of the rotational energy, and the energy recovery device helps to improve the overall performance of the unit; the air discharged from the low-pressure end of the air expander 8 enters the regenerator 5 for heat exchange Exhaust directly into the air.

The working process of the heat pump water heater of the present invention is as follows:

The air compressor 1 is driven by external power equipment to inhale air from the external environment 11 and compress it. The compressed air becomes high temperature and high pressure air, and enters the heating water tank 3 through the first connecting pipe 2 to heat the water in the water tank. After the heating is completed, the air enters the regenerator 5 through the second connecting pipe 4, and exchanges heat with the air at the outlet of the air expander in the regenerator 5, and the temperature is further reduced; the air flowing out of the regenerator 5 passes through the first cycle The connecting pipe 6 enters the air expander 8, and the work pressure of the air expander 8 drops during the process. The work done by the air expander 8 is transmitted to the air compressor 1 through the transmission coupling 7 to realize the recovery of work, and the air expander The air from the outlet of the machine 8 enters the regenerator 5 through the second circulation connecting pipe 9, exchanges heat with the air flowing out of the heating water tank 3 in the regenerator 5, and the temperature rises, and finally discharges into the environment through the exhaust pipe 10 , to complete the cycle.

The above descriptions of the embodiments are for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (6)

1. a Teat pump boiler for semi-open type backheating type air compressing circulation, is characterized in that, comprises air compressor (1), heating water tank (3), regenerator (5) and air expander (8), described air compressor (1) is communicated with heating water tank (3) inlet end, air compressor (1) is from external environment (11) air amount and compress, air after overcompression becomes HTHP air, and HTHP air enters in heating water tank (3) water in water tank is heated, described regenerator (5) is communicated with heating water tank (3) outlet side, heating water tank (3) air out enters in regenerator (5) and carries out heat exchange, regenerator (5) outlet side directly passes into external environment (11), between described air expander (8) and regenerator (5), be communicated with and form closed circuit, and be connected by transmission coupling (7) between air expander (8) and air compressor (1), air expander (8) absorbs the heat acting of flowing out air in regenerator (5), and merit is passed to air compressor (1) and is realized the recovery of merit by transmission coupling (7).

2. the Teat pump boiler of a kind of semi-open type backheating type air compressing circulation according to claim 1, it is characterized in that, the entrance of described air compressor (1) is communicated with external environment (11) by air inlet pipe (12), the outlet of described air compressor (1) is connected to the inlet end of heating water tank (3) by the first tube connector (2), the outlet side of heating water tank (3) is connected with the inlet end of regenerator (5) by the second tube connector (4), the outlet side of regenerator (5) passes in external environment (11) by blast pipe (10), between described regenerator (5) and air expander (8) high-pressure side, be communicated with by the first circulation tube connector (6), and be communicated with by the second circulation tube connector (9) between air expander (8) low-pressure end, between regenerator (5) and air expander (8), form closed circuit.

3. the Teat pump boiler of a kind of semi-open type backheating type air compressing circulation according to claim 1 and 2, is characterized in that, described air compressor (1) is turbo-compressor.

4. the Teat pump boiler of a kind of semi-open type backheating type air compressing circulation according to claim 1 and 2, is characterized in that, described heating water tank (3) internal placement have with water tank in the water air heat-exchange passage that carries out heat exchange.

5. the Teat pump boiler of a kind of semi-open type backheating type air compressing circulation according to claim 1 and 2, is characterized in that, described regenerator (5) is single-phase fluid heat exchanger.

6. the Teat pump boiler of a kind of semi-open type backheating type air compressing circulation according to claim 1 and 2, is characterized in that, described air expander (8) is turbine type air expander.

Images