The last financial crisis demonstrated once again that such events happen with regularity. Instead of a random event which can be imagined  as the result of  a series of mistakes, including  problems with financial regulation, a cyclic process is observed. Periods of cycles can vary, but the trend is evident:  main stages are  present in each of the financial cycles. Recently it was pointed out that such a financial cyclic process is quite similar to a Carnot's cycle for the heat machine. By exploring the analogy with thermodynamics we develop the econophysical model of a "financial heat machine". We see, that while in physics a perpetuum mobile is absolutely impossible, in economics such mobile may exist under some conditions. Our thermodynamical model for the financial market induces a rather unusual interpretation of the role of financial crises. In opposition to the common point of view, in our model financial crises play a crucial role in the functioning of the modern financial market. This is an important (concluding) stage of a financial cycle that is analogous to the stage of cooling in the ordinary Carnot cycle. A financial cycle could not be completed without such a stage as well as the ordinary Carnot cycle. Thus, inspite of its destructive (at the first sight) consequences, the stage or financial crisis is as important as the stage of "boiling of the financial market" ("heating of expectations").