CN103148584B - Two-stage compression heat pump Hot water units - Google Patents

Abstract

The invention relates to a two-stage compression heat pump hot water unit, which is characterized in that it includes a first compressor, an evaporator, a coupling intercooler, a first throttling device, a second compressor, a condenser, a second throttling device, an intermediate The warm water pool and the high temperature pool are equipped with a heat exchanger in the coupled intercooler, and the exhaust port of the first compressor is connected with the coupled intercooler; after the evaporator is connected in series with the first throttling device, one end is connected to the first compressor The air inlet of the compressor is connected, and the other end is connected with the coupled intercooler; the air inlet of the second compressor is connected with the coupled intercooler; after the condenser is connected in series with the second throttling device, one end is connected with the discharge of the second compressor The air port is connected, and the other end is connected with the coupling intercooler. It can simultaneously generate medium-temperature circulating hot water at about 55°C and high-temperature circulating hot water at about 80°C, with high comprehensive energy efficiency ratio, good economy and stable operation.

Description

Two-stage compression heat pump water heater unit

technical field

The invention relates to a two-stage compression heat pump technology, in particular to an externally coupled two-stage compression, two-stage throttling, complete intermediate cooling and high-temperature heat pump hot water unit for generating industrial circulating hot water.

Background technique

Heat pump technology is a high-efficiency energy utilization technology, which is widely used in many aspects of life and production. At present, the maximum hot water temperature produced by single-stage compression heat pump hot water units developed by heat pump technology is generally below 60°C, while in industrial production, such as electroplating, clothing, food and slaughtering industries, a large number of industries need circulating hot water around 80°C , single-stage compression technology is difficult to effectively solve. Using cascade heat pump technology and two-stage compression heat pump technology can produce hot water at 80°C, but compared with a single-stage heat pump system that produces hot water at a temperature of about 55°C, the energy efficiency ratio of the system is relatively low, and the above-mentioned high-temperature heat pump There is a coupling problem between the high-temperature heat pump system and the low-temperature heat pump system of the unit. If the coupling between the two stages is not good, the energy efficiency ratio of the unit will be further reduced, and the operation stability of the unit will be poor. Based on the above reasons, its application in industrial production has been greatly restricted. Only by effectively solving the above problems can the heat pump technology be more widely used and exert greater economic and social benefits.

Contents of the invention

The purpose of the present invention is to provide a two-stage compression heat pump hot water unit, which can simultaneously generate medium-temperature circulating hot water at about 55°C and high-temperature circulating hot water at about 80°C, and meet the needs of large-scale use of circulating heat at about 55°C and about 80°C. The place where the water is used, especially the place where the material can be heated in sections, makes the unit have high comprehensive energy efficiency ratio, good economy and stable operation.

In order to achieve the above object, the present invention is achieved in that it is a two-stage compression heat pump water heater unit, which is characterized in that it includes:

first compressor;

A coupling intercooler, a heat exchanger is arranged in the coupling intercooler, and the exhaust port of the low-pressure stage refrigerant of the first compressor communicates with the coupling intercooler;

An evaporator and a first throttling device. After the evaporator is connected in series with the first throttling device, one end of the evaporator communicates with the air inlet of the first compressor, and the other end communicates with the coupled intercooler;

The second compressor, the air inlet of the second compressor communicates with the coupling intercooler;

A condenser and a second throttling device. After the condenser is connected in series with the second throttling device, one end communicates with the exhaust port of the second compressor, and the other end communicates with the coupled intercooler;

A medium-temperature water pool, the water outlet and the water inlet of the medium-temperature water pool are communicated with the water inlet and the water outlet of the heat exchanger respectively through two connecting pipes, and a first water pump is provided on a connecting pipe; and

A high-temperature water pool, the water outlet and water inlet of the high-temperature water pool are communicated with the water inlet and water outlet of the condenser through two connecting pipes, and a second water pump is arranged on a connecting pipe; the high-temperature water pool and the medium-temperature water pool are connected through the connecting pipe They communicate with each other, and a first cut-off valve is arranged on the connection pipe connecting the high-temperature water pool and the medium-temperature water pool.

The high-temperature water pool and the medium-temperature water pool are communicated through two connecting pipes, the first shut-off valve is arranged on one of the connecting pipes, and the second shut-off valve and the third water pump are arranged on the other connecting pipe.

The coupled intercooler includes an intermediate cavity, a left water cavity, and a right water cavity; the intermediate cavity is respectively provided with an exhaust inlet pipe for low-pressure refrigerant, a liquid supply outlet pipe for low-pressure refrigerant, The liquid return inlet pipe of the high-pressure refrigerant and the air return outlet pipe of the high-pressure refrigerant, the exhaust inlet pipe communicates with the exhaust port of the first compressor, and the liquid supply outlet pipe communicates with the first throttling device The inlet is communicated, the liquid return inlet pipe is communicated with the gas inlet of the second compressor, and the return air outlet pipe is communicated with the gas outlet of the second throttling device; the left water chamber is arranged on the left side of the middle cavity and Separated from each other, a water inlet pipe is provided on the left water chamber; the right water chamber is arranged on the right side of the middle chamber and is isolated from each other, and a water outlet pipe is provided on the right water chamber; the heat exchanger is arranged in the middle chamber , one end of the heat exchanger communicates with the left water chamber, and the other end communicates with the right water chamber; the water outlet of the medium-temperature water pool communicates with the water inlet pipe of the left water chamber through a connecting pipe, and the water inlet of the medium-temperature water pool communicates with the water inlet through a connecting pipe. The outlet pipes of the right water cavity are connected.

The mouth of the exhaust gas inlet pipe and the mouth of the liquid return inlet pipe are both deep in the middle cavity and below the liquid level of the refrigerant, and the mouth of the return air outlet pipe is located in the middle cavity and above the liquid level of the refrigerant , the nozzle of the liquid supply outlet pipe is located at the bottom of the middle cavity.

The heat exchanger includes more than two heat exchange tubes, and the heat exchange tubes can be metal straight tubes, metal helical tubes or metal coiled tubes.

The present invention has the following advantages relative to the prior art:

1) Due to the external coupling system, the operating conditions of the low-temperature heat pump system and the high-temperature heat pump system can be well adjusted, so that the two-stage heat pump system is well coupled and the energy efficiency ratio of the unit is improved;

2) Part of the generated heat is used as the heat-absorbing heat source of the high-temperature heat pump system, and the other part is used to produce medium-temperature hot water for the production process of medium-temperature heating, and the overall energy efficiency ratio of the unit has been greatly improved.

Description of drawings

Fig. 1 is a structure and flow diagram of the present invention;

Fig. 2 is the structural representation of coupling intercooler of the present invention;

Fig. 3 is a schematic diagram of the electric appliance control of the present invention.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In the description of the present invention, the terms "first", "second" and "third" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

As shown in Figures 1 and 2, it is a two-stage compression heat pump water heater unit, which includes:

first compressor 1;

Coupling intercooler 2, in which a heat exchanger 210 is arranged, and the exhaust port of the low-pressure refrigerant of the first compressor 1 communicates with the coupling intercooler 2;

An evaporator 4 and a first throttling device 3. After the evaporator 4 is connected in series with the first throttling device 3, one end communicates with the air inlet of the first compressor 1, and the other end communicates with the coupled intercooler 2;

The second compressor 5, the air inlet of the second compressor 5 communicates with the coupling intercooler 2;

Condenser 6 and second throttling device 7. After the condenser 6 is connected in series with the second throttling device 7, one end communicates with the exhaust port of the second compressor 5, and the other end communicates with the coupled intercooler 2 ;

A medium-temperature water pool 9, the water outlet and the water inlet of the medium-temperature water pool 9 are respectively communicated with the water inlet and the water outlet of the heat exchanger 210 through two connecting pipes, and a first water pump 8 is provided on a connecting pipe; and

High-temperature pool 13, the water outlet and the water inlet of the high-temperature pool 13 communicate with the water inlet and the water outlet of the condenser 6 through two connecting pipes respectively, and a second water pump 14 is arranged on a connecting pipe; The warm water pool 9 communicates through a connecting pipe, and a first shut-off valve 11 is provided on the connecting pipe between the high temperature water pool 13 and the medium temperature water pool 9 .

In this embodiment, the high-temperature pool 13 communicates with the medium-temperature pool 9 through two connecting pipes, the first shut-off valve 11 is provided on one of the connecting pipes, and the second connecting pipe is provided on the other connecting pipe. Stop valve 10 and the third water pump 12.

During operation, the refrigerant gas from the evaporator 4 is compressed by the first compressor 1 and becomes a high-temperature and high-pressure gas, enters the coupling intercooler 2, is condensed into a liquid and is stored in the coupling intercooler 2, and stored in the coupling intercooler 2. The refrigerant liquid in the device 2 becomes a low-temperature and low-pressure liquid after being throttled by the first throttling device 3, and then turns into a refrigerant gas after exchanging heat with an external heat source through the evaporator 4, and then returns to the first compressor 1 to complete Low temperature heat pump system circulation. The refrigerant gas from the coupling intercooler 2 is compressed by the second compressor 5 and becomes a high-temperature and high-pressure gas, and is condensed into a high-pressure liquid after exchanging heat with the circulating water from the high-temperature water pool 13 in the condenser 6, and then passes through the second throttling The device 7 becomes a low-temperature and low-pressure liquid after throttling, enters the coupling intercooler 2, and the refrigerant gas generated in the coupling intercooler 2 returns to the compressor 5 to complete the cycle of the high-temperature heat pump system. The circulating water in the high-temperature pool 13 is heated after exchanging heat with the second water pump 14 and the condenser 6 for the high-temperature heating production process. The circulating water in the medium-temperature water pool 9 is heated by the first water pump 8 after exchanging heat with the refrigerant liquid in the coupled intercooler 2 to meet the needs of the medium-temperature heating production process. When the unit is in operation due to the coupling control, the low-temperature heat pump system needs to stop running and the high-temperature heat pump needs to continue to run, the circulating water in the medium-temperature pool 9 continues to circulate through the first water pump 8, and uses its own heat to reversely couple the intercooler 2 The refrigerant liquid in the system is heated and used as the heat-absorbing heat source of the high-temperature heat pump system to meet the operation needs of the high-temperature heat pump system.

As shown in Figure 2, in this embodiment, the coupling intercooler 2 includes an intermediate cavity 22, a left water cavity 21 and a right water cavity 24; The exhaust inlet pipe 27 of the refrigerant, the liquid supply outlet pipe 23 of the low-pressure refrigerant, the liquid return inlet pipe 29 of the high-pressure refrigerant, and the return air outlet pipe 28 of the high-pressure refrigerant, the exhaust inlet pipe 27 and the first The exhaust port of a compressor 1 communicates, the liquid supply outlet pipe 23 communicates with the inlet of the first throttling device 3, the liquid return inlet pipe 29 communicates with the gas inlet of the second compressor 5, and the return gas The outlet pipe 28 communicates with the air outlet of the second throttling device 7; the left water chamber 21 is arranged on the left side of the middle chamber 22 and is isolated from each other, and a water inlet pipe 212 is provided on the left water chamber 21; The chamber 24 is arranged on the right side of the middle chamber 22 and is isolated from each other. The water outlet pipe 25 is arranged on the right water chamber 24; Cavity 21 is connected, and the other end is connected with the right water chamber 24; the water outlet of the middle temperature water pool 9 is connected with the water inlet pipe 212 of the left water chamber 21 through the connecting pipe, and the water inlet of the middle temperature water pool 9 is connected with the right water chamber through the connecting pipe. The outlet pipe 25 of 24 communicates.

As shown in Figure 2, in this embodiment, the nozzle of the exhaust gas inlet pipe 27 and the nozzle of the liquid return inlet pipe 29 are all deep into the intermediate cavity 22 and located below the liquid level of the refrigerant, and the return gas The nozzle of the outlet pipe 28 is located in the middle cavity 22 and above the refrigerant liquid level, and the nozzle of the liquid supply outlet pipe 23 is located at the bottom of the middle cavity 22 .

As shown in FIG. 2 , in this embodiment, the heat exchanger 210 includes more than two heat exchange tubes, and the heat exchange tubes may be metal straight tubes, metal spiral tubes or metal coiled tubes.

As shown in Figure 3, the control of the present invention is realized in this way: when the unit is initially running, the water temperature in the medium-temperature pool 9 and the high-temperature pool 13 is normal temperature, and the switch SB8 is closed, and the first water pump 8 starts to run, and the medium-temperature water The water in the pool 9 starts to circulate, and simultaneously opens the first shut-off valve 11 and the second shut-off valve 10 on the communication pipeline between the medium-temperature pool 9 and the high-temperature pool 13, closes the switch SB12, and the third water pump 12 starts running, so that The water in the middle temperature pool 9 and the high temperature pool 13 circulates inside. At this time, the water temperature sensor T of the medium-temperature pool is in a closed state, and the fan of the evaporator 4 and the first compressor 1 in the low-temperature heat pump system of the unit start to run. T high starts to rise at the same time, and when it reaches the set lower limit temperature T1 of the medium-temperature pool, the switch SB12 is turned off, the third water pump 12 stops running, and the second shut-off valve 10 and the first shut-off valve 11 are closed. Close the switch SB14, the second water pump 14 starts to run, and the water in the high-temperature pool 13 starts to circulate. When the water temperature T in 13 reaches the set upper limit temperature T4, the high temperature heat pump system stops working. When the water temperature Thigh of the high temperature pool 13 drops to the set lower limit temperature T3, the high temperature heat pump system is restarted. When the water temperature T in the middle temperature pool 9 reaches the set upper limit temperature T2, the low temperature heat pump system stops running. At this time, if the high-temperature heat pump system still needs to continue to operate, because the water in the medium-temperature water pool 9 is always circulating, it can in turn heat the refrigerant liquid in the coupled intercooler 2 as a heat-absorbing heat source for the high-temperature heat pump system, ensuring The normal operation of the high temperature heat pump system. When the water temperature T in the middle temperature pool 9 drops to the set lower limit temperature T1, the low temperature heat pump system is restarted. The upper and lower limit temperatures T4 and T3 of the water temperature T in the high-temperature pool 13 are determined by the production process, and the upper and lower limit temperatures T2 and T1 of the water temperature T in the medium-temperature pool 9 are set according to the operating evaporation temperature of the low-temperature heat pump system and The condensing temperature of the high-temperature heat pump system is adjusted to control the middle temperature of the two-stage heat pump system, so that the two are well coupled.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (3)

1. A two-stage compression heat pump hot water unit, characterized in that it comprises: first compressor (1); Coupling intercooler (2); the coupling intercooler (2) includes an intermediate cavity (22), a left water cavity (21) and a right water cavity (24); wherein on the intermediate cavity (22) The exhaust inlet pipe (27) of the low-pressure refrigerant, the liquid supply outlet pipe (23) of the low-pressure refrigerant, the return liquid inlet pipe (29) of the high-pressure refrigerant and the gas return outlet of the high-pressure refrigerant are respectively provided pipe (28), the exhaust inlet pipe (27) communicates with the exhaust port of the low-pressure refrigerant of the first compressor (1), and the left water chamber (21) is set in the middle chamber (22) The left side is isolated from each other, and the water inlet pipe (212) is provided on the left water chamber (21); 24) is provided with an outlet pipe (25); the heat exchanger (210) is arranged in the middle cavity (22), and one end of the heat exchanger (210) communicates with the left water cavity (21), and the other end communicates with the right Water cavity (24) Unicom; The evaporator (4) and the first throttling device (3). After the evaporator (4) is connected in series with the first throttling device (3), one end communicates with the air inlet of the first compressor (1), and the other end Connect with the liquid supply outlet pipe (23); The second compressor (5), the air inlet of the second compressor (5) communicates with the return air outlet pipe (28); A condenser (6) and a second throttling device (7). After the condenser (6) is connected in series with the second throttling device (7), one end of the condenser (6) communicates with the exhaust port of the second compressor (5), The other end communicates with the liquid return inlet pipe (29); Medium-temperature water pool (9), the water outlet of the medium-temperature water pool (9) communicates with the water inlet pipe (212) of the left water chamber (21) through a connecting pipe, and the water inlet of the medium-temperature water pool (9) communicates with the right water inlet through a connecting pipe. The outlet pipes (25) of the water cavity (24) are connected, and a first water pump (8) is provided on a connecting pipe; and A high-temperature water pool (13), the water outlet and water inlet of the high-temperature water pool (13) are respectively communicated with the water inlet and water outlet of the condenser (6) through two connecting pipes, and a second water pump ( 14); the high-temperature water pool (13) and the medium-temperature water pool (9) are connected through two connecting pipes, a first stop valve (11) is provided on one connecting pipe, and a first stop valve (11) is provided on the other connecting pipe. Two stop valves (10) and the third water pump (12). 2. The two-stage compression heat pump water heater unit according to claim 1, characterized in that the mouth of the exhaust inlet pipe (27) and the mouth of the return liquid inlet pipe (29) are all deep into the middle cavity (22 ) and below the liquid level of the refrigerant, the nozzle of the return air outlet pipe (28) is located in the intermediate cavity (22) and above the liquid level of the refrigerant, the nozzle of the liquid supply outlet pipe (23) Located at the bottom of the middle cavity (22). 3. The two-stage compression heat pump water heater unit according to claim 1, characterized in that the heat exchanger (210) includes more than two heat exchange tubes, and the heat exchange tubes are metal straight tubes or metal spiral tubes or metal coils.